diff --git a/pyproject.toml b/pyproject.toml
index 440b6c07..aa778f3e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "sap-cloud-sdk"
-version = "0.31.0"
+version = "0.32.0"
 description = "SAP Cloud SDK for Python"
 readme = "README.md"
 license = "Apache-2.0"
diff --git a/src/sap_cloud_sdk/agentgateway/__init__.py b/src/sap_cloud_sdk/agentgateway/__init__.py
index e70b7275..69c5f1e8 100644
--- a/src/sap_cloud_sdk/agentgateway/__init__.py
+++ b/src/sap_cloud_sdk/agentgateway/__init__.py
@@ -63,6 +63,7 @@
 from sap_cloud_sdk.agentgateway.agw_client import create_client, AgentGatewayClient
 from sap_cloud_sdk.agentgateway.exceptions import (
     AgentGatewaySDKError,
+    AgentGatewayServerError,
     MCPServerNotFoundError,
 )
 
@@ -82,5 +83,6 @@
     "AgentCardFilter",
     # Exceptions
     "AgentGatewaySDKError",
+    "AgentGatewayServerError",
     "MCPServerNotFoundError",
 ]
diff --git a/src/sap_cloud_sdk/agentgateway/_customer.py b/src/sap_cloud_sdk/agentgateway/_customer.py
index be5019ea..dd846ced 100644
--- a/src/sap_cloud_sdk/agentgateway/_customer.py
+++ b/src/sap_cloud_sdk/agentgateway/_customer.py
@@ -26,14 +26,20 @@
 )
 from sap_cloud_sdk.agentgateway._token_cache import _TokenCache
 from sap_cloud_sdk.agentgateway.exceptions import AgentGatewaySDKError
+from sap_cloud_sdk.core.secret_resolver import resolve_base_mount
 
 logger = logging.getLogger(__name__)
 
-# Environment variable to override default credential path
+# Environment variable to override default credential path (points directly to credentials file)
 _CREDENTIALS_PATH_ENV = "AGW_CREDENTIALS_PATH"
 
-# Default credential path for Kyma production deployments
-_CREDENTIALS_DEFAULT_PATH = "/etc/ums/credentials/credentials"
+# servicebinding.io: scan $SERVICE_BINDING_ROOT for a binding whose 'type' file equals the expected type
+_BINDING_TYPE = "integration-credentials"
+_BINDING_TYPE_FILE = "type"
+_CREDENTIALS_FILE = "credentials"
+
+# Kyma default when SERVICE_BINDING_ROOT is not set
+_DEFAULT_BINDING_ROOT = "/bindings"
 
 # Resource URN for Agent Gateway token scope (hardcoded - production value)
 _AGW_RESOURCE_URN = "urn:sap:identity:application:provider:name:agent-gateway"
@@ -66,24 +72,38 @@ def detect_customer_agent_credentials() -> str | None:
     """Check if customer agent credentials file exists.
 
     Checks for credential file in the following order:
-    1. Path specified in AGW_CREDENTIALS_PATH env var
-    2. Default mounted path: /etc/ums/credentials/credentials
+    1. Path specified in AGW_CREDENTIALS_PATH env var (explicit override, points to file directly)
+    2. $SERVICE_BINDING_ROOT (or /bindings if unset): scans all subdirectories for one whose
+       'type' file contains 'integration-credentials', then reads 'credentials' from that directory
 
     Returns:
         Path to credentials file if found, None otherwise.
     """
-    # Check env var first (path may be customized)
+    # 1. Explicit override via env var
     path_from_env = os.environ.get(_CREDENTIALS_PATH_ENV)
     if path_from_env and os.path.isfile(path_from_env):
         logger.debug("Customer credentials found at env var path: %s", path_from_env)
         return path_from_env
 
-    # Check default mounted path
-    if os.path.isfile(_CREDENTIALS_DEFAULT_PATH):
-        logger.debug(
-            "Customer credentials found at default path: %s", _CREDENTIALS_DEFAULT_PATH
-        )
-        return _CREDENTIALS_DEFAULT_PATH
+    # 2. servicebinding.io: scan $SERVICE_BINDING_ROOT for a binding whose 'type' file equals _BINDING_TYPE
+    sbr = resolve_base_mount(_DEFAULT_BINDING_ROOT)
+    if sbr and os.path.isdir(sbr):
+        for entry in os.scandir(sbr):
+            if not entry.is_dir():
+                continue
+            type_file = os.path.join(entry.path, _BINDING_TYPE_FILE)
+            if not os.path.isfile(type_file):
+                continue
+            with open(type_file) as f:
+                if f.read().strip() != _BINDING_TYPE:
+                    continue
+            credentials_path = os.path.join(entry.path, _CREDENTIALS_FILE)
+            if os.path.isfile(credentials_path):
+                logger.debug(
+                    "Customer credentials found via servicebinding.io type scan: %s",
+                    credentials_path,
+                )
+                return credentials_path
 
     return None
 
@@ -128,16 +148,17 @@ def load_customer_credentials(path: str) -> CustomerCredentials:
     if _CredentialFields.INTEGRATION_DEPENDENCIES not in data:
         raise AgentGatewaySDKError(
             "Credentials file missing required field: integrationDependencies. "
-            'Expected format: [{"ordId": "...", "data": {"globalTenantId": "..."}}]'
+            'Expected format: [{"ordId": "...", "globalTenantId": "..."}]'
         )
 
     try:
         integration_deps = [
             IntegrationDependency(
                 ord_id=dep[_CredentialFields.ORD_ID],
-                global_tenant_id=dep[_CredentialFields.DATA][
-                    _CredentialFields.GLOBAL_TENANT_ID
-                ],
+                global_tenant_id=(
+                    dep.get(_CredentialFields.GLOBAL_TENANT_ID)
+                    or dep[_CredentialFields.DATA][_CredentialFields.GLOBAL_TENANT_ID]
+                ),
             )
             for dep in data[_CredentialFields.INTEGRATION_DEPENDENCIES]
         ]
@@ -148,7 +169,7 @@ def load_customer_credentials(path: str) -> CustomerCredentials:
     except (KeyError, TypeError) as e:
         raise AgentGatewaySDKError(
             f"Failed to parse integrationDependencies: {e}. "
-            'Expected format: [{"ordId": "...", "data": {"globalTenantId": "..."}}]'
+            'Expected format: [{"ordId": "...", "globalTenantId": "..."}]'
         )
 
     return CustomerCredentials(
@@ -216,7 +237,6 @@ def _request_token_mtls(
     credentials: CustomerCredentials,
     grant_type: str,
     timeout: float,
-    app_tid: str | None = None,
     extra_data: dict | None = None,
 ) -> dict:
     """Make mTLS token request to IAS.
@@ -225,7 +245,6 @@ def _request_token_mtls(
         credentials: Customer credentials with certificate and private key.
         grant_type: OAuth2 grant type.
         timeout: HTTP timeout in seconds.
-        app_tid: BTP Application Tenant ID of subscriber (optional).
         extra_data: Additional form data for the token request.
 
     Returns:
@@ -242,11 +261,6 @@ def _request_token_mtls(
         "resource": _AGW_RESOURCE_URN,
     }
 
-    # TODO: app_tid requirement is still being clarified with the IBD team.
-    # This parameter may be removed if it turns out to be unnecessary.
-    if app_tid:
-        data["app_tid"] = app_tid
-
     if extra_data:
         data.update(extra_data)
 
@@ -326,7 +340,6 @@ def get_system_token_mtls(
         credentials,
         grant_type=_GRANT_TYPE_CLIENT_CREDENTIALS,
         timeout=timeout,
-        app_tid=app_tid,
         extra_data={"response_type": "token"},
     )
     access_token = token_data["access_token"]
@@ -372,15 +385,17 @@ def exchange_user_token(
             return cached_token
 
     logger.info("Exchanging user token for AGW-scoped token via jwt-bearer grant")
+    extra: dict = {
+        "assertion": user_token,
+        "token_format": "jwt",
+    }
+    if app_tid:
+        extra["app_tid"] = app_tid
     token_data = _request_token_mtls(
         credentials,
         grant_type=_GRANT_TYPE_JWT_BEARER,
         timeout=timeout,
-        app_tid=app_tid,
-        extra_data={
-            "assertion": user_token,
-            "token_format": "jwt",
-        },
+        extra_data=extra,
     )
     access_token = token_data["access_token"]
 
@@ -476,26 +491,64 @@ async def _list_server_tools(
                 ]
 
 
+def _resolve_dependency(
+    credentials: CustomerCredentials,
+    ord_id: str,
+) -> IntegrationDependency:
+    """Resolve a single IntegrationDependency by ORD ID.
+
+    Args:
+        credentials: Customer credentials with integrationDependencies.
+        ord_id: ORD ID to look up.
+
+    Returns:
+        The matching IntegrationDependency.
+
+    Raises:
+        AgentGatewaySDKError: If no match is found or multiple entries share the same ORD ID.
+    """
+    matches = [d for d in credentials.integration_dependencies if d.ord_id == ord_id]
+    if not matches:
+        available = ", ".join(d.ord_id for d in credentials.integration_dependencies)
+        raise AgentGatewaySDKError(
+            f"ORD ID '{ord_id}' not found in integrationDependencies. "
+            f"Available: {available or '(none)'}"
+        )
+    if len(matches) > 1:
+        tids = ", ".join(m.global_tenant_id for m in matches)
+        raise AgentGatewaySDKError(
+            f"ORD ID '{ord_id}' matches multiple integrationDependencies with "
+            f"different tenant IDs ({tids}). Specify the tenant ID explicitly."
+        )
+    return matches[0]
+
+
 async def get_mcp_tools_customer(
     credentials: CustomerCredentials,
     system_token: str,
     timeout: float,
+    ord_id: str | None = None,
 ) -> list[MCPTool]:
-    """List all MCP tools from servers defined in credentials.
+    """List MCP tools from servers defined in credentials.
 
-    Iterates over all integrationDependencies in the credentials file and
-    discovers tools from each MCP server using a pre-fetched system token.
+    When ord_id is given, only tools from that single dependency are returned
+    and the tenant ID is derived automatically from the credentials.
+    When ord_id is omitted, tools from all integrationDependencies are returned.
 
     Args:
         credentials: Customer credentials with integrationDependencies.
         system_token: Pre-fetched raw system token for authentication.
         timeout: HTTP timeout in seconds for MCP server calls.
+        ord_id: Optional ORD ID to filter to a single server. The tenant ID
+            is derived from the credentials — no need to pass it separately.
+            Raises AgentGatewaySDKError if the ORD ID matches multiple entries.
 
     Returns:
-        List of MCPTool objects from all servers.
+        List of MCPTool objects from the matching server(s).
 
     Raises:
-        AgentGatewaySDKError: If integrationDependencies is empty.
+        AgentGatewaySDKError: If integrationDependencies is empty, or if ord_id
+            is given but not found or matches multiple tenant IDs.
     """
     dependencies = credentials.integration_dependencies
 
@@ -504,6 +557,9 @@ async def get_mcp_tools_customer(
             "integrationDependencies is empty in credentials — no MCP servers configured."
         )
 
+    if ord_id is not None:
+        dependencies = [_resolve_dependency(credentials, ord_id)]
+
     logger.info("Discovering tools from %d MCP server(s)", len(dependencies))
 
     tools: list[MCPTool] = []
diff --git a/src/sap_cloud_sdk/agentgateway/_mcp_session.py b/src/sap_cloud_sdk/agentgateway/_mcp_session.py
new file mode 100644
index 00000000..c704648e
--- /dev/null
+++ b/src/sap_cloud_sdk/agentgateway/_mcp_session.py
@@ -0,0 +1,93 @@
+"""Shared helpers for MCP session management."""
+
+import logging
+import uuid
+
+import httpx
+from mcp import ClientSession, McpError
+from mcp.client.streamable_http import streamable_http_client
+
+from sap_cloud_sdk.agentgateway._models import MCPTool
+from sap_cloud_sdk.agentgateway.exceptions import AgentGatewayServerError
+
+logger = logging.getLogger(__name__)
+
+
+async def invoke_mcp_tool(
+    tool: MCPTool, auth_token: str, timeout: float, **kwargs
+) -> str:
+    """Open an MCP session, call a tool, and return its text result.
+
+    Handles McpError from both initialize() and call_tool(), and checks
+    result.isError, raising AgentGatewayServerError in all three cases.
+
+    Args:
+        tool: MCPTool to invoke.
+        auth_token: Raw bearer token for the Authorization header.
+        timeout: HTTP timeout in seconds.
+        **kwargs: Tool input parameters forwarded to call_tool().
+
+    Returns:
+        Tool result as a string, or "" if the response has no content.
+
+    Raises:
+        AgentGatewayServerError: If the server returns any kind of error.
+    """
+    async with httpx.AsyncClient(
+        headers={
+            "Authorization": f"Bearer {auth_token}",
+            "x-correlation-id": str(uuid.uuid4()),
+        },
+        timeout=timeout,
+    ) as http_client:
+        try:
+            async with streamable_http_client(tool.url, http_client=http_client) as (
+                read,
+                write,
+                _,
+            ):
+                async with ClientSession(read, write) as session:
+                    try:
+                        await session.initialize()
+                    except McpError as e:
+                        raise AgentGatewayServerError(
+                            f"Agent Gateway rejected MCP session for tool '{tool.name}': {e.error.message}",
+                            error_code=e.error.code,
+                        ) from e
+                    try:
+                        result = await session.call_tool(tool.name, kwargs)
+                    except McpError as e:
+                        raise AgentGatewayServerError(
+                            f"Agent Gateway returned error for tool '{tool.name}': {e.error.message}",
+                            error_code=e.error.code,
+                        ) from e
+                    if result is None:
+                        logger.warning("Tool '%s' returned a null result", tool.name)
+                        return ""
+                    if result.isError:
+                        raise AgentGatewayServerError(
+                            f"Tool '{tool.name}' returned an error: {_error_text(result.content)}"
+                        )
+                    if not result.content:
+                        return ""
+                    return str(getattr(result.content[0], "text", ""))
+        except BaseExceptionGroup as eg:
+            # anyio wraps task-group exceptions into ExceptionGroups. If the only
+            # leaf exception is AttributeError it means an older MCP library version
+            # crashed on a null result body inside call_tool. Re-raise anything else.
+            attr_errors, rest = eg.split(AttributeError)
+            if rest is not None:
+                raise
+            logger.warning(
+                "Tool '%s' returned a null result (MCP null-result bug: %s)",
+                tool.name,
+                attr_errors,
+            )
+            return ""
+
+
+def _error_text(content: list) -> str:
+    """Extract a human-readable message from MCP error content blocks."""
+    texts = [getattr(block, "text", None) for block in content]
+    message = " ".join(t for t in texts if t)
+    return message or "unknown error"
diff --git a/src/sap_cloud_sdk/agentgateway/agw_client.py b/src/sap_cloud_sdk/agentgateway/agw_client.py
index 411ff4a8..2eabb540 100644
--- a/src/sap_cloud_sdk/agentgateway/agw_client.py
+++ b/src/sap_cloud_sdk/agentgateway/agw_client.py
@@ -300,6 +300,7 @@ async def list_mcp_tools(
         self,
         user_token: str | Callable[[], str] | None = None,
         app_tid: str | None = None,
+        ord_id: str | None = None,
     ) -> list[MCPTool]:
         """List all MCP tools from MCP servers.
 
@@ -320,12 +321,17 @@ async def list_mcp_tools(
                 If provided, uses user-scoped auth instead of system auth.
             app_tid: BTP Application Tenant ID of the subscriber.
                 Only used for customer agents.
+            ord_id: ORD ID of the MCP server to filter to (customer agents only).
+                The tenant ID is derived automatically from the credentials.
+                When omitted, tools from all integrationDependencies are returned.
+                Raises AgentGatewaySDKError if the ORD ID matches multiple entries.
 
         Returns:
             List of MCPTool objects from all MCP servers.
 
         Raises:
-            AgentGatewaySDKError: If credential loading or token acquisition fails.
+            AgentGatewaySDKError: If credential loading or token acquisition fails,
+                or if ord_id does not match exactly one entry in integrationDependencies.
 
         Example:
             ```python
@@ -333,6 +339,11 @@ async def list_mcp_tools(
             for tool in tools:
                 print(f"{tool.name}: {tool.description}")
 
+            # Filter to a specific ORD (tenant ID resolved from credentials):
+            tools = await agw_client.list_mcp_tools(
+                ord_id="sap.s4:apiResource:API_PRODUCT_0002_MCP:v1"
+            )
+
             # With user token for principal propagation:
             tools = await agw_client.list_mcp_tools(user_token="user-jwt")
             ```
@@ -350,7 +361,7 @@ async def list_mcp_tools(
                 else:
                     auth = await self.get_system_auth(app_tid=app_tid)
                 return await get_mcp_tools_customer(
-                    credentials, auth.access_token, self._config.timeout
+                    credentials, auth.access_token, self._config.timeout, ord_id=ord_id
                 )
 
             # LoB flow - requires tenant_subdomain
@@ -367,7 +378,6 @@ async def list_mcp_tools(
             )
 
         except AgentGatewaySDKError:
-            # Re-raise SDK errors as-is
             raise
         except Exception as e:
             logger.exception("Unexpected error during tool discovery")
@@ -443,9 +453,10 @@ async def list_agent_cards(
     @record_metrics(Module.AGENTGATEWAY, Operation.AGENTGATEWAY_CALL_MCP_TOOL)
     async def call_mcp_tool(
         self,
-        tool: MCPTool,
+        tool: MCPTool | str,
         user_token: str | Callable[[], str] | None = None,
         app_tid: str | None = None,
+        ord_id: str | None = None,
         **kwargs,
     ) -> str:
         """Invoke an MCP tool.
@@ -460,7 +471,9 @@ async def call_mcp_tool(
             provided, falls back to system token (no principal propagation).
 
         Args:
-            tool: MCPTool object (from list_mcp_tools).
+            tool: MCPTool object (from list_mcp_tools) or tool name as a string.
+                When a string is given, list_mcp_tools is called first to resolve
+                the MCPTool. For customer agents, ord_id must also be provided.
             user_token: User's JWT for principal propagation.
                 Can be a string or a callable returning a string.
                 Required for LoB agents.
@@ -470,6 +483,8 @@ async def call_mcp_tool(
                 for tenant-scoped token exchange.
                 TODO: This parameter's requirement is still being clarified with
                 the IBD team and may be removed if unnecessary.
+            ord_id: ORD ID used to resolve the MCPTool when tool is given as a string
+                (customer agents only). The tenant ID is derived from the credentials.
             **kwargs: Tool input parameters (passed directly to the tool).
 
         Returns:
@@ -477,16 +492,23 @@ async def call_mcp_tool(
 
         Raises:
             AgentGatewaySDKError: If user_token or tenant_subdomain is required
-                but not provided (LoB flow), or if token exchange/tool invocation fails.
+                but not provided (LoB flow), if tool name cannot be resolved, or if
+                token exchange/tool invocation fails.
 
         Example:
             ```python
-            # Note: kwargs are tool-specific input parameters.
-            # Check tool.input_schema for expected parameters.
+            # Pass an MCPTool object directly:
             result = await agw_client.call_mcp_tool(
                 tool=tools[0],
                 user_token="user-jwt",
-                order_id="12345",  # example tool-specific parameter
+                order_id="12345",
+            )
+
+            # Or pass the tool name as a string (ord_id required for customer agents):
+            result = await agw_client.call_mcp_tool(
+                tool="list_ProductPlantCosting_for_sap_self",
+                ord_id="sap.s4:apiResource:API_PRODUCT_0002_MCP:v1",
+                user_token="user-jwt",
             )
             ```
         """
@@ -498,6 +520,11 @@ async def call_mcp_tool(
                     "Customer agent credentials detected at '%s'", credentials_path
                 )
 
+                if isinstance(tool, str):
+                    tool = await self._resolve_tool_by_name(
+                        tool, ord_id, user_token, app_tid
+                    )
+
                 # Resolve user_token if provided (optional for customer flow)
                 if user_token:
                     auth = await self.get_user_auth(user_token, app_tid)
@@ -519,6 +546,11 @@ async def call_mcp_tool(
             if app_tid:
                 logger.warning("app_tid parameter ignored for LoB agent flow")
 
+            if isinstance(tool, str):
+                tool = await self._resolve_tool_by_name(
+                    tool, ord_id, user_token, app_tid
+                )
+
             auth = await self.get_user_auth(user_token, app_tid)
             return await call_mcp_tool_lob(
                 tool, auth.access_token, self._config.timeout, **kwargs
@@ -530,10 +562,44 @@ async def call_mcp_tool(
         except Exception as e:
             logger.exception("Unexpected error during tool invocation")
             cause = _unwrap_exception_group(e)
+            tool_label = tool if isinstance(tool, str) else tool.name
             raise AgentGatewaySDKError(
-                f"Tool invocation failed for '{tool.name}': {cause}"
+                f"Tool invocation failed for '{tool_label}': {cause}"
             ) from e
 
+    async def _resolve_tool_by_name(
+        self,
+        tool_name: str,
+        ord_id: str | None,
+        user_token: str | Callable[[], str] | None,
+        app_tid: str | None,
+    ) -> MCPTool:
+        """Look up a tool by name via list_mcp_tools.
+
+        Args:
+            tool_name: Name of the tool to resolve.
+            ord_id: ORD ID to narrow the search (customer agents).
+            user_token: Forwarded to list_mcp_tools for auth.
+            app_tid: Forwarded to list_mcp_tools for auth.
+
+        Returns:
+            The matching MCPTool.
+
+        Raises:
+            AgentGatewaySDKError: If no tool with that name is found.
+        """
+        tools = await self.list_mcp_tools(
+            user_token=user_token, app_tid=app_tid, ord_id=ord_id
+        )
+        match = next((t for t in tools if t.name == tool_name), None)
+        if match is None:
+            available = ", ".join(t.name for t in tools[:10])
+            raise AgentGatewaySDKError(
+                f"Tool '{tool_name}' not found. "
+                f"Available tools{' (first 10)' if len(tools) > 10 else ''}: {available or '(none)'}"
+            )
+        return match
+
 
 def _unwrap_exception_group(exc: BaseException) -> BaseException:
     """Unwrap nested ExceptionGroups to present meaningful error messages."""
diff --git a/src/sap_cloud_sdk/agentgateway/exceptions.py b/src/sap_cloud_sdk/agentgateway/exceptions.py
index 5d96e21f..b88a017c 100644
--- a/src/sap_cloud_sdk/agentgateway/exceptions.py
+++ b/src/sap_cloud_sdk/agentgateway/exceptions.py
@@ -22,3 +22,22 @@ class MCPServerNotFoundError(AgentGatewaySDKError):
     """
 
     pass
+
+
+class AgentGatewayServerError(AgentGatewaySDKError):
+    """Raised when the Agent Gateway server returns an error response.
+
+    This error occurs when:
+    - The MCP server card is not found in the registry
+    - The server returns a JSON-RPC error (e.g. code -32600)
+    - A tool invocation returns an error result (isError=True)
+
+    Attributes:
+        error_code: JSON-RPC error code, if available.
+        server_message: The raw error message from the server.
+    """
+
+    def __init__(self, message: str, error_code: int | None = None):
+        super().__init__(message)
+        self.error_code = error_code
+        self.server_message = message
diff --git a/src/sap_cloud_sdk/agentgateway/user-guide.md b/src/sap_cloud_sdk/agentgateway/user-guide.md
index 813ed2e0..245feda8 100644
--- a/src/sap_cloud_sdk/agentgateway/user-guide.md
+++ b/src/sap_cloud_sdk/agentgateway/user-guide.md
@@ -18,21 +18,48 @@ pip install sap-cloud-sdk[langchain]
 
 Customer agents use file-based credentials with mTLS authentication. MCP servers are read from `integrationDependencies` in the credentials file.
 
+#### Credential Detection
+
+The SDK looks for credentials in the following order:
+
+1. **`AGW_CREDENTIALS_PATH`** env var — direct path to a JSON credentials file.
+2. **`SERVICE_BINDING_ROOT`** env var — scans all subdirectories for one whose `type` file contains `integration-credentials`, then reads `credentials` from that directory (servicebinding.io format).
+3. **`/bindings`** — same scan as above, used as the default when `SERVICE_BINDING_ROOT` is not set.
+
+**servicebinding.io layout** (used on BTP Kyma / Kubernetes):
+
+```
+$SERVICE_BINDING_ROOT/
+└── my-agw-binding/
+    ├── type          # must contain "integration-credentials"
+    ├── instance_name # optional, ignored by the SDK
+    └── credentials   # JSON credentials object
+```
+
+**Flat file** (used with `AGW_CREDENTIALS_PATH`):
+
+```
+/path/to/credentials.json   # JSON credentials object
+```
+
 ```python
 from sap_cloud_sdk.agentgateway import create_client
 
 agw_client = create_client()
 
-# Discover tools (reads all servers from credentials integrationDependencies)
-tools = await agw_client.list_mcp_tools()
+# Discover tools from all servers in integrationDependencies
+tools = await agw_client.list_mcp_tools(user_token="user-jwt")
 
 for tool in tools:
     print(f"{tool.name}: {tool.description}")
 
-# Discover tools with user principal propagation
-tools = await agw_client.list_mcp_tools(user_token="user-jwt")
+# Filter to a specific ORD ID — tenant ID is derived from credentials automatically
+tools = await agw_client.list_mcp_tools(
+    user_token="user-jwt",
+    ord_id="sap.s4:apiResource:API_PRODUCT_0002_MCP:v1",
+)
 
-# Invoke a tool with user principal propagation
+# Invoke a tool — pass the MCPTool object directly
 result = await agw_client.call_mcp_tool(
     tool=tools[0],
     user_token="user-jwt",
@@ -40,6 +67,8 @@ result = await agw_client.call_mcp_tool(
 )
 ```
 
+> **Note:** AGW currently requires a user token for all tool calls (principal propagation). Passing `user_token` is therefore required for customer agents.
+
 ### LoB Agent Flow
 
 LoB agents use BTP Destination Service for credential management. Tools and A2A agents are auto-discovered from destination fragments.
@@ -189,14 +218,14 @@ class AgentGatewayClient:
     async def list_mcp_tools(
         self,
         user_token: str | Callable[[], str] | None = None,
-        app_tid: str | None = None,
+        ord_id: str | None = None,
     ) -> list[MCPTool]
 
     async def call_mcp_tool(
         self,
-        tool: MCPTool,
+        tool: MCPTool | str,
         user_token: str | Callable[[], str] | None = None,
-        app_tid: str | None = None,
+        ord_id: str | None = None,
         **kwargs,
     ) -> str
 
@@ -240,3 +269,19 @@ class MCPTool:
     url: str
     fragment_name: str | None
 ```
+
+#### `list_mcp_tools`
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `user_token` | `str \| Callable[[], str] \| None` | User JWT for principal propagation. When provided, a jwt-bearer token exchange is performed instead of a system token request. |
+| `ord_id` | `str \| None` | ORD ID to filter results to a single MCP server. The tenant ID is derived from the credentials — no need to pass it separately. Raises `AgentGatewaySDKError` if the ORD ID matches multiple `integrationDependencies` entries. |
+
+#### `call_mcp_tool`
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `tool` | `MCPTool \| str` | The tool to invoke. Pass an `MCPTool` object (from `list_mcp_tools`) or a tool name as a string. When a string is given, `list_mcp_tools` is called first to resolve the tool — provide `ord_id` to narrow the lookup. |
+| `user_token` | `str \| Callable[[], str] \| None` | User JWT for principal propagation. Required for LoB agents; optional for customer agents (falls back to system token). |
+| `ord_id` | `str \| None` | ORD ID used to resolve the tool when `tool` is given as a string. The tenant ID is derived from the credentials automatically. |
+| `**kwargs` | | Tool input parameters forwarded directly to the MCP tool. See `tool.input_schema` for expected fields. |
diff --git a/tests/agentgateway/unit/test_agw_client.py b/tests/agentgateway/unit/test_agw_client.py
index b1541fa5..f7667c2d 100644
--- a/tests/agentgateway/unit/test_agw_client.py
+++ b/tests/agentgateway/unit/test_agw_client.py
@@ -521,7 +521,7 @@ async def test_customer_flow_passes_system_token(self):
             await agw_client.list_mcp_tools(app_tid="tid")
 
             mock_customer.assert_called_once_with(
-                mock_creds, "customer-system-token", 60.0
+                mock_creds, "customer-system-token", 60.0, ord_id=None
             )
 
     @pytest.mark.asyncio
@@ -575,7 +575,7 @@ async def test_customer_flow_with_user_token_uses_user_auth(self):
             await agw_client.list_mcp_tools(user_token="user-jwt", app_tid="tid")
 
             mock_customer.assert_called_once_with(
-                mock_creds, "exchanged-user-token", 60.0
+                mock_creds, "exchanged-user-token", 60.0, ord_id=None
             )
 
 
diff --git a/tests/agentgateway/unit/test_customer.py b/tests/agentgateway/unit/test_customer.py
index 4469ab47..9069b9a5 100644
--- a/tests/agentgateway/unit/test_customer.py
+++ b/tests/agentgateway/unit/test_customer.py
@@ -11,11 +11,15 @@
     get_system_token_mtls,
     exchange_user_token,
     get_mcp_tools_customer,
-    call_mcp_tool_customer,
     _build_mcp_url,
+    _resolve_dependency,
     _CREDENTIALS_PATH_ENV,
-    _CREDENTIALS_DEFAULT_PATH,
+    _BINDING_TYPE,
+    _BINDING_TYPE_FILE,
+    _CREDENTIALS_FILE,
+    _DEFAULT_BINDING_ROOT,
 )
+from sap_cloud_sdk.agentgateway._mcp_session import invoke_mcp_tool as call_mcp_tool_customer
 from sap_cloud_sdk.agentgateway._models import (
     CustomerCredentials,
     IntegrationDependency,
@@ -23,7 +27,7 @@
 )
 from sap_cloud_sdk.agentgateway._token_cache import _TokenCache
 from sap_cloud_sdk.agentgateway.config import ClientConfig
-from sap_cloud_sdk.agentgateway.exceptions import AgentGatewaySDKError
+from sap_cloud_sdk.agentgateway.exceptions import AgentGatewaySDKError, AgentGatewayServerError
 
 
 # ============================================================
@@ -34,6 +38,15 @@
 class TestDetectCustomerAgentCredentials:
     """Tests for customer agent credential detection."""
 
+    def _make_binding(self, parent, name="my-binding"):
+        """Create a servicebinding.io-compliant binding directory under parent."""
+        binding_dir = parent / name
+        binding_dir.mkdir(parents=True, exist_ok=True)
+        (binding_dir / _BINDING_TYPE_FILE).write_text(_BINDING_TYPE)
+        creds_file = binding_dir / _CREDENTIALS_FILE
+        creds_file.write_text('{"clientid": "test"}')
+        return creds_file
+
     def test_detect_from_env_var_path(self, tmp_path):
         """Detect credentials from path specified in environment variable."""
         creds_file = tmp_path / "credentials.json"
@@ -43,53 +56,82 @@ def test_detect_from_env_var_path(self, tmp_path):
             result = detect_customer_agent_credentials()
             assert result == str(creds_file)
 
-    def test_detect_from_env_var_path_file_not_exists(self):
+    def test_detect_from_env_var_path_file_not_exists(self, tmp_path):
         """Return None when env var path doesn't exist."""
-        with patch.dict(os.environ, {_CREDENTIALS_PATH_ENV: "/nonexistent/path"}):
+        env = {_CREDENTIALS_PATH_ENV: "/nonexistent/path", "SERVICE_BINDING_ROOT": str(tmp_path)}
+        with patch.dict(os.environ, env, clear=False):
             result = detect_customer_agent_credentials()
             assert result is None
 
-    def test_detect_from_default_path(self):
-        """Detect credentials from default mounted path."""
-        with patch.dict(os.environ, {}, clear=False):
-            # Remove env var if present
+    def test_detect_from_service_binding_root(self, tmp_path):
+        """Detect credentials by scanning SERVICE_BINDING_ROOT for a binding with matching type file."""
+        creds_file = self._make_binding(tmp_path)
+
+        env = {"SERVICE_BINDING_ROOT": str(tmp_path)}
+        with patch.dict(os.environ, env, clear=False):
             os.environ.pop(_CREDENTIALS_PATH_ENV, None)
+            result = detect_customer_agent_credentials()
+            assert result == str(creds_file)
 
-            with patch("os.path.isfile") as mock_isfile:
-                mock_isfile.side_effect = lambda p: p == _CREDENTIALS_DEFAULT_PATH
+    def test_detect_from_default_path(self, tmp_path):
+        """Detect credentials from default /bindings root when SERVICE_BINDING_ROOT is not set."""
+        creds_file = self._make_binding(tmp_path)
 
+        with patch.dict(os.environ, {}, clear=False):
+            os.environ.pop(_CREDENTIALS_PATH_ENV, None)
+            os.environ.pop("SERVICE_BINDING_ROOT", None)
+            with patch("sap_cloud_sdk.agentgateway._customer._DEFAULT_BINDING_ROOT", str(tmp_path)):
                 result = detect_customer_agent_credentials()
-                assert result == _CREDENTIALS_DEFAULT_PATH
+                assert result == str(creds_file)
 
-    def test_no_credentials_returns_none(self):
-        """Return None when no credentials are found."""
-        with patch.dict(os.environ, {}, clear=False):
+    def test_skips_binding_with_wrong_type(self, tmp_path):
+        """Ignore binding directories whose type file does not match."""
+        wrong_dir = tmp_path / "other-binding"
+        wrong_dir.mkdir()
+        (wrong_dir / _BINDING_TYPE_FILE).write_text("something-else")
+        (wrong_dir / _CREDENTIALS_FILE).write_text('{"clientid": "wrong"}')
+
+        env = {"SERVICE_BINDING_ROOT": str(tmp_path)}
+        with patch.dict(os.environ, env, clear=False):
             os.environ.pop(_CREDENTIALS_PATH_ENV, None)
+            result = detect_customer_agent_credentials()
+            assert result is None
 
-            with patch("os.path.isfile", return_value=False):
-                result = detect_customer_agent_credentials()
-                assert result is None
+    def test_service_binding_root_takes_priority_over_default(self, tmp_path):
+        """SERVICE_BINDING_ROOT is checked before the hardcoded /bindings fallback."""
+        sbr_dir = tmp_path / "sbr"
+        sbr_dir.mkdir()
+        creds_file = self._make_binding(sbr_dir)
 
-    def test_env_var_takes_priority_over_default(self, tmp_path):
-        """Env var path should take priority over default path."""
-        creds_file = tmp_path / "custom_credentials.json"
-        creds_file.write_text('{"clientid": "custom"}')
+        with patch.dict(os.environ, {"SERVICE_BINDING_ROOT": str(sbr_dir)}, clear=False):
+            os.environ.pop(_CREDENTIALS_PATH_ENV, None)
+            result = detect_customer_agent_credentials()
+            assert result == str(creds_file)
 
-        with patch.dict(os.environ, {_CREDENTIALS_PATH_ENV: str(creds_file)}):
-            # Even if default path exists, env var should be used
-            with patch("os.path.isfile") as mock_isfile:
+    def test_no_credentials_returns_none(self, tmp_path):
+        """Return None when no binding with matching type is found."""
+        env = {"SERVICE_BINDING_ROOT": str(tmp_path)}
+        with patch.dict(os.environ, env, clear=False):
+            os.environ.pop(_CREDENTIALS_PATH_ENV, None)
+            result = detect_customer_agent_credentials()
+            assert result is None
 
-                def isfile_side_effect(path):
-                    if path == str(creds_file):
-                        return True
-                    if path == _CREDENTIALS_DEFAULT_PATH:
-                        return True
-                    return False
+    def test_env_var_takes_priority_over_service_binding_root(self, tmp_path):
+        """AGW_CREDENTIALS_PATH env var takes priority over SERVICE_BINDING_ROOT."""
+        creds_file = tmp_path / "custom_credentials.json"
+        creds_file.write_text('{"clientid": "custom"}')
 
-                mock_isfile.side_effect = isfile_side_effect
+        sbr_dir = tmp_path / "sbr"
+        sbr_dir.mkdir()
+        self._make_binding(sbr_dir)
 
-                result = detect_customer_agent_credentials()
-                assert result == str(creds_file)
+        env = {
+            _CREDENTIALS_PATH_ENV: str(creds_file),
+            "SERVICE_BINDING_ROOT": str(sbr_dir),
+        }
+        with patch.dict(os.environ, env, clear=False):
+            result = detect_customer_agent_credentials()
+            assert result == str(creds_file)
 
 
 # ============================================================
@@ -112,7 +154,7 @@ def test_loads_valid_credentials(self, tmp_path):
             "integrationDependencies": [
                 {
                     "ordId": "sap.test:apiResource:demo:v1",
-                    "data": {"globalTenantId": "123"},
+                    "globalTenantId": "123",
                 },
             ],
         }
@@ -172,11 +214,11 @@ def test_loads_integration_dependencies(self, tmp_path):
             "integrationDependencies": [
                 {
                     "ordId": "sap.mcpbuilder:apiResource:cost-center:v1",
-                    "data": {"globalTenantId": "250695"},
+                    "globalTenantId": "250695",
                 },
                 {
                     "ordId": "sap.flights:mcpServer:v1",
-                    "data": {"globalTenantId": "892451733"},
+                    "globalTenantId": "892451733",
                 },
             ],
         }
@@ -194,6 +236,35 @@ def test_loads_integration_dependencies(self, tmp_path):
         assert result.integration_dependencies[1].ord_id == "sap.flights:mcpServer:v1"
         assert result.integration_dependencies[1].global_tenant_id == "892451733"
 
+    def test_loads_nested_service_binding_integration_dependencies(self, tmp_path):
+        """Load service binding integrationDependencies when tenant id is nested under data."""
+        creds_file = tmp_path / "credentials.json"
+        creds_data = {
+            "tokenServiceUrl": "https://ias.example.com/oauth2/token",
+            "clientid": "my-client-id",
+            "certificate": "-----BEGIN CERTIFICATE-----\ntest\n-----END CERTIFICATE-----",
+            "privateKey": "-----BEGIN PRIVATE KEY-----\ntest\n-----END PRIVATE KEY-----",
+            "gatewayUrl": "https://agw.example.com",
+            "integrationDependencies": [
+                {
+                    "ordId": "sap.s4:apiResource:CE_COSTCENTER_0001_MCP:v1",
+                    "data": {
+                        "globalTenantId": "731473562",
+                    },
+                },
+            ],
+        }
+        creds_file.write_text(json.dumps(creds_data))
+
+        result = load_customer_credentials(str(creds_file))
+
+        assert len(result.integration_dependencies) == 1
+        assert (
+            result.integration_dependencies[0].ord_id
+            == "sap.s4:apiResource:CE_COSTCENTER_0001_MCP:v1"
+        )
+        assert result.integration_dependencies[0].global_tenant_id == "731473562"
+
     def test_raises_when_integration_dependencies_missing(self, tmp_path):
         """Raise error when integrationDependencies is not in credentials file."""
         creds_file = tmp_path / "credentials.json"
@@ -222,7 +293,7 @@ def test_raises_on_invalid_integration_dependencies_format(self, tmp_path):
             "privateKey": "-----BEGIN PRIVATE KEY-----\ntest\n-----END PRIVATE KEY-----",
             "gatewayUrl": "https://agw.example.com",
             "integrationDependencies": [
-                {"ordId": "missing-data-field"},  # Missing 'data' key
+                {"ordId": "missing-global-tenant-id-field"},  # Missing 'globalTenantId' key
             ],
         }
         creds_file.write_text(json.dumps(creds_data))
@@ -493,6 +564,54 @@ def test_reuses_cached_user_token(self, credentials):
         mock_request.assert_called_once()
 
 
+# ============================================================
+# Test: _resolve_dependency
+# ============================================================
+
+
+class TestResolveDependency:
+    """Tests for ORD ID → tenant ID resolution."""
+
+    def _make_credentials(self, deps):
+        return CustomerCredentials(
+            token_service_url="https://ias.example.com/oauth2/token",
+            client_id="test-client",
+            certificate="cert",
+            private_key="key",
+            gateway_url="https://agw.example.com",
+            integration_dependencies=deps,
+        )
+
+    def test_resolves_matching_ord_id(self):
+        """Return the dependency whose ord_id matches."""
+        dep = IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="111")
+        creds = self._make_credentials([dep])
+        assert _resolve_dependency(creds, "sap.s4:apiResource:FOO:v1") is dep
+
+    def test_raises_when_not_found(self):
+        """Raise error when the ORD ID is not in the list."""
+        creds = self._make_credentials([
+            IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="111"),
+        ])
+        with pytest.raises(AgentGatewaySDKError, match="not found in integrationDependencies"):
+            _resolve_dependency(creds, "sap.s4:apiResource:BAR:v1")
+
+    def test_raises_on_multiple_matches(self):
+        """Raise error when the same ORD ID appears with different tenant IDs."""
+        creds = self._make_credentials([
+            IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="111"),
+            IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="222"),
+        ])
+        with pytest.raises(AgentGatewaySDKError, match="matches multiple integrationDependencies"):
+            _resolve_dependency(creds, "sap.s4:apiResource:FOO:v1")
+
+    def test_raises_with_empty_dependencies(self):
+        """Raise error when integrationDependencies is empty."""
+        creds = self._make_credentials([])
+        with pytest.raises(AgentGatewaySDKError, match="not found in integrationDependencies"):
+            _resolve_dependency(creds, "sap.s4:apiResource:FOO:v1")
+
+
 # ============================================================
 # Test: get_mcp_tools_customer
 # ============================================================
@@ -611,13 +730,84 @@ async def mock_list_tools(*args, **kwargs):
             assert len(result) == 1
             assert result[0].name == "tool2"
 
+    @pytest.mark.asyncio
+    async def test_filters_to_single_server_when_ord_id_given(self):
+        """Only query the server whose ord_id matches when ord_id is provided."""
+        credentials = CustomerCredentials(
+            token_service_url="https://ias.example.com/oauth2/token",
+            client_id="test-client",
+            certificate="cert",
+            private_key="key",
+            gateway_url="https://agw.example.com",
+            integration_dependencies=[
+                IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="111"),
+                IntegrationDependency(ord_id="sap.s4:apiResource:BAR:v1", global_tenant_id="222"),
+            ],
+        )
+        mock_tool = MCPTool(
+            name="foo_tool", server_name="FOO", description="", input_schema={},
+            url="https://agw.example.com/v1/mcp/sap.s4:apiResource:FOO:v1/111",
+        )
+
+        with patch(
+            "sap_cloud_sdk.agentgateway._customer._list_server_tools",
+            new_callable=AsyncMock,
+            return_value=[mock_tool],
+        ) as mock_list:
+            result = await get_mcp_tools_customer(
+                credentials, "token", 60.0, ord_id="sap.s4:apiResource:FOO:v1"
+            )
+
+        assert len(result) == 1
+        assert result[0].name == "foo_tool"
+        assert mock_list.call_count == 1
+        called_url = mock_list.call_args[0][0]
+        assert "FOO" in called_url and "111" in called_url
+
+    @pytest.mark.asyncio
+    async def test_raises_when_ord_id_not_found(self):
+        """Raise error when the given ord_id is not in integrationDependencies."""
+        credentials = CustomerCredentials(
+            token_service_url="https://ias.example.com/oauth2/token",
+            client_id="test-client",
+            certificate="cert",
+            private_key="key",
+            gateway_url="https://agw.example.com",
+            integration_dependencies=[
+                IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="111"),
+            ],
+        )
+        with pytest.raises(AgentGatewaySDKError, match="not found in integrationDependencies"):
+            await get_mcp_tools_customer(
+                credentials, "token", 60.0, ord_id="sap.s4:apiResource:MISSING:v1"
+            )
+
+    @pytest.mark.asyncio
+    async def test_raises_when_ord_id_matches_multiple(self):
+        """Raise error when the given ord_id matches multiple entries."""
+        credentials = CustomerCredentials(
+            token_service_url="https://ias.example.com/oauth2/token",
+            client_id="test-client",
+            certificate="cert",
+            private_key="key",
+            gateway_url="https://agw.example.com",
+            integration_dependencies=[
+                IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="111"),
+                IntegrationDependency(ord_id="sap.s4:apiResource:FOO:v1", global_tenant_id="222"),
+            ],
+        )
+        with pytest.raises(AgentGatewaySDKError, match="matches multiple integrationDependencies"):
+            await get_mcp_tools_customer(
+                credentials, "token", 60.0, ord_id="sap.s4:apiResource:FOO:v1"
+            )
+
 
 # ============================================================
-# Test: call_mcp_tool_customer
+# Test: invoke_mcp_tool (via customer flow)
 # ============================================================
 
 
-class TestCallMcpToolCustomer:
+class TestInvokeMcpTool:
     """Tests for customer flow tool invocation."""
 
     @pytest.fixture
@@ -656,13 +846,13 @@ async def test_calls_tool_with_pre_fetched_token(self, credentials, mock_tool):
         """Call tool using pre-fetched auth token."""
         with (
             patch(
-                "httpx.AsyncClient",
+                "sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient",
             ) as mock_client_class,
             patch(
-                "sap_cloud_sdk.agentgateway._customer.streamable_http_client",
+                "sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client",
             ) as mock_stream,
             patch(
-                "sap_cloud_sdk.agentgateway._customer.ClientSession",
+                "sap_cloud_sdk.agentgateway._mcp_session.ClientSession",
             ) as mock_session_class,
         ):
             # Set up mock chain
@@ -681,6 +871,7 @@ async def test_calls_tool_with_pre_fetched_token(self, credentials, mock_tool):
             mock_session = AsyncMock()
             mock_session.initialize = AsyncMock()
             mock_result = MagicMock()
+            mock_result.isError = False
             mock_content = MagicMock()
             mock_content.text = "Order created successfully"
             mock_result.content = [mock_content]
@@ -705,13 +896,13 @@ async def test_returns_empty_string_when_no_content(self, credentials, mock_tool
         """Return empty string when tool returns no content."""
         with (
             patch(
-                "httpx.AsyncClient",
+                "sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient",
             ) as mock_client_class,
             patch(
-                "sap_cloud_sdk.agentgateway._customer.streamable_http_client",
+                "sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client",
             ) as mock_stream,
             patch(
-                "sap_cloud_sdk.agentgateway._customer.ClientSession",
+                "sap_cloud_sdk.agentgateway._mcp_session.ClientSession",
             ) as mock_session_class,
         ):
             mock_client = AsyncMock()
@@ -729,6 +920,7 @@ async def test_returns_empty_string_when_no_content(self, credentials, mock_tool
             mock_session = AsyncMock()
             mock_session.initialize = AsyncMock()
             mock_result = MagicMock()
+            mock_result.isError = False
             mock_result.content = []
             mock_session.call_tool = AsyncMock(return_value=mock_result)
             mock_session_ctx = AsyncMock()
@@ -741,3 +933,195 @@ async def test_returns_empty_string_when_no_content(self, credentials, mock_tool
             )
 
             assert result == ""
+
+    @pytest.mark.asyncio
+    async def test_returns_empty_string_when_result_is_none(self, mock_tool):
+        """Return empty string when call_tool returns None (null MCP response)."""
+        with (
+            patch("sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient") as mock_client_class,
+            patch("sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client") as mock_stream,
+            patch("sap_cloud_sdk.agentgateway._mcp_session.ClientSession") as mock_session_class,
+        ):
+            mock_client = AsyncMock()
+            mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+            mock_client.__aexit__ = AsyncMock(return_value=None)
+            mock_client_class.return_value = mock_client
+
+            mock_stream_ctx = AsyncMock()
+            mock_stream_ctx.__aenter__ = AsyncMock(return_value=(AsyncMock(), AsyncMock(), None))
+            mock_stream_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_stream.return_value = mock_stream_ctx
+
+            mock_session = AsyncMock()
+            mock_session.initialize = AsyncMock()
+            mock_session.call_tool = AsyncMock(return_value=None)
+            mock_session_ctx = AsyncMock()
+            mock_session_ctx.__aenter__ = AsyncMock(return_value=mock_session)
+            mock_session_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_session_class.return_value = mock_session_ctx
+
+            result = await call_mcp_tool_customer(mock_tool, "auth-token", 60.0)
+            assert result == ""
+
+    @pytest.mark.asyncio
+    async def test_returns_empty_string_when_exception_group_contains_only_attr_error(self, mock_tool):
+        """Return empty string when anyio wraps an AttributeError (older MCP null-result bug) in an ExceptionGroup."""
+        with (
+            patch("sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient") as mock_client_class,
+            patch("sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client") as mock_stream,
+            patch("sap_cloud_sdk.agentgateway._mcp_session.ClientSession") as mock_session_class,
+        ):
+            mock_client = AsyncMock()
+            mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+            mock_client.__aexit__ = AsyncMock(return_value=None)
+            mock_client_class.return_value = mock_client
+
+            # Simulate anyio wrapping the AttributeError in a BaseExceptionGroup
+            nested = BaseExceptionGroup(
+                "unhandled errors in a TaskGroup",
+                [BaseExceptionGroup(
+                    "unhandled errors in a TaskGroup",
+                    [AttributeError("'NoneType' object has no attribute 'isError'")],
+                )],
+            )
+            mock_stream_ctx = AsyncMock()
+            mock_stream_ctx.__aenter__ = AsyncMock(return_value=(AsyncMock(), AsyncMock(), None))
+            mock_stream_ctx.__aexit__ = AsyncMock(side_effect=nested)
+            mock_stream.return_value = mock_stream_ctx
+
+            mock_session_class.return_value = AsyncMock()
+
+            result = await call_mcp_tool_customer(mock_tool, "auth-token", 60.0)
+            assert result == ""
+
+    @pytest.mark.asyncio
+    async def test_raises_server_error_when_result_is_error(self, mock_tool):
+        """Raise AgentGatewayServerError when tool result has isError=True."""
+        with (
+            patch("sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient") as mock_client_class,
+            patch(
+                "sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client"
+            ) as mock_stream,
+            patch(
+                "sap_cloud_sdk.agentgateway._mcp_session.ClientSession"
+            ) as mock_session_class,
+        ):
+            mock_client = AsyncMock()
+            mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+            mock_client.__aexit__ = AsyncMock(return_value=None)
+            mock_client_class.return_value = mock_client
+
+            mock_stream_ctx = AsyncMock()
+            mock_stream_ctx.__aenter__ = AsyncMock(
+                return_value=(AsyncMock(), AsyncMock(), None)
+            )
+            mock_stream_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_stream.return_value = mock_stream_ctx
+
+            mock_session = AsyncMock()
+            mock_session.initialize = AsyncMock()
+            mock_result = MagicMock()
+            mock_result.isError = True
+            error_content = MagicMock()
+            error_content.text = "Internal tool error"
+            mock_result.content = [error_content]
+            mock_session.call_tool = AsyncMock(return_value=mock_result)
+            mock_session_ctx = AsyncMock()
+            mock_session_ctx.__aenter__ = AsyncMock(return_value=mock_session)
+            mock_session_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_session_class.return_value = mock_session_ctx
+
+            with pytest.raises(AgentGatewayServerError, match="Internal tool error"):
+                await call_mcp_tool_customer(mock_tool, "auth-token", 60.0)
+
+    @pytest.mark.asyncio
+    async def test_raises_server_error_on_mcp_error_during_call(self, mock_tool):
+        """Raise AgentGatewayServerError when MCP call_tool raises McpError."""
+        from mcp import McpError
+        from mcp.types import ErrorData
+
+        with (
+            patch("sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient") as mock_client_class,
+            patch(
+                "sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client"
+            ) as mock_stream,
+            patch(
+                "sap_cloud_sdk.agentgateway._mcp_session.ClientSession"
+            ) as mock_session_class,
+        ):
+            mock_client = AsyncMock()
+            mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+            mock_client.__aexit__ = AsyncMock(return_value=None)
+            mock_client_class.return_value = mock_client
+
+            mock_stream_ctx = AsyncMock()
+            mock_stream_ctx.__aenter__ = AsyncMock(
+                return_value=(AsyncMock(), AsyncMock(), None)
+            )
+            mock_stream_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_stream.return_value = mock_stream_ctx
+
+            mock_session = AsyncMock()
+            mock_session.initialize = AsyncMock()
+            mock_session.call_tool = AsyncMock(
+                side_effect=McpError(
+                    ErrorData(
+                        code=-32600,
+                        message="MCP server card for ORD ID sap.mcpbuilder:apiResource:API_SALES_ORDE_SRV_MCP_1:v1 not found in registry",
+                    )
+                )
+            )
+            mock_session_ctx = AsyncMock()
+            mock_session_ctx.__aenter__ = AsyncMock(return_value=mock_session)
+            mock_session_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_session_class.return_value = mock_session_ctx
+
+            with pytest.raises(
+                AgentGatewayServerError,
+                match="not found in registry",
+            ) as exc_info:
+                await call_mcp_tool_customer(mock_tool, "auth-token", 60.0)
+
+            assert exc_info.value.error_code == -32600
+
+    @pytest.mark.asyncio
+    async def test_raises_server_error_on_mcp_error_during_initialize(self, mock_tool):
+        """Raise AgentGatewayServerError when MCP initialize raises McpError."""
+        from mcp import McpError
+        from mcp.types import ErrorData
+
+        with (
+            patch("sap_cloud_sdk.agentgateway._mcp_session.httpx.AsyncClient") as mock_client_class,
+            patch(
+                "sap_cloud_sdk.agentgateway._mcp_session.streamable_http_client"
+            ) as mock_stream,
+            patch(
+                "sap_cloud_sdk.agentgateway._mcp_session.ClientSession"
+            ) as mock_session_class,
+        ):
+            mock_client = AsyncMock()
+            mock_client.__aenter__ = AsyncMock(return_value=mock_client)
+            mock_client.__aexit__ = AsyncMock(return_value=None)
+            mock_client_class.return_value = mock_client
+
+            mock_stream_ctx = AsyncMock()
+            mock_stream_ctx.__aenter__ = AsyncMock(
+                return_value=(AsyncMock(), AsyncMock(), None)
+            )
+            mock_stream_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_stream.return_value = mock_stream_ctx
+
+            mock_session = AsyncMock()
+            mock_session.initialize = AsyncMock(
+                side_effect=McpError(ErrorData(code=-32600, message="Unauthorized"))
+            )
+            mock_session_ctx = AsyncMock()
+            mock_session_ctx.__aenter__ = AsyncMock(return_value=mock_session)
+            mock_session_ctx.__aexit__ = AsyncMock(return_value=None)
+            mock_session_class.return_value = mock_session_ctx
+
+            with pytest.raises(
+                AgentGatewayServerError,
+                match="rejected MCP session.*Unauthorized",
+            ):
+                await call_mcp_tool_customer(mock_tool, "auth-token", 60.0)
diff --git a/tests/agentgateway/unit/test_lob.py b/tests/agentgateway/unit/test_lob.py
index 39c036e5..2505e554 100644
--- a/tests/agentgateway/unit/test_lob.py
+++ b/tests/agentgateway/unit/test_lob.py
@@ -618,6 +618,7 @@ async def test_calls_tool_with_pre_fetched_token(self):
         )
 
         mock_result = MagicMock()
+        mock_result.isError = False
         mock_result.content = [MagicMock()]
         mock_result.content[0].text = "Tool result"
 
@@ -670,6 +671,7 @@ async def test_returns_empty_string_when_no_content(self):
         )
 
         mock_result = MagicMock()
+        mock_result.isError = False
         mock_result.content = []
 
         with (