diff --git a/CHANGELOG.md b/CHANGELOG.md
index dffc48e..75fe1ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,9 +2,12 @@
 
 - Dependency updates
 
+# v1.5.3 - 2026-05-27
+
+- Add destructive hints for tools.
+
 # v1.5.2 - 2026-05-27
 
-- Add destructive hints for tools
 - Enable OpenAI connectors in OAuth
 
 # v1.5.0 - 2026-05-26
diff --git a/package-lock.json b/package-lock.json
index b5c5c35..9ad05b6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "browserless-mcp",
-  "version": "1.3.4",
+  "version": "1.5.3",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "browserless-mcp",
-      "version": "1.3.4",
+      "version": "1.5.3",
       "hasInstallScript": true,
       "license": "SSPL-1.0",
       "dependencies": {
diff --git a/test/tools/annotations.spec.ts b/test/tools/annotations.spec.ts
new file mode 100644
index 0000000..f7169cc
--- /dev/null
+++ b/test/tools/annotations.spec.ts
@@ -0,0 +1,79 @@
+import { expect } from 'chai';
+import sinon from 'sinon';
+import { FastMCP } from 'fastmcp';
+import { registerSmartScraperTool } from '../../src/tools/smartscraper.js';
+import { registerFunctionTool } from '../../src/tools/function.js';
+import { registerDownloadTool } from '../../src/tools/download.js';
+import { registerExportTool } from '../../src/tools/export.js';
+import { registerAgentTools } from '../../src/tools/agent.js';
+import { registerSearchTool } from '../../src/tools/search.js';
+import { registerMapTool } from '../../src/tools/map.js';
+import { registerCrawlTool } from '../../src/tools/crawl.js';
+import { registerPerformanceTool } from '../../src/tools/performance.js';
+import type { McpConfig } from '../../src/@types/types.js';
+
+const mockConfig: McpConfig = {
+  browserlessToken: 'test-token',
+  browserlessApiUrl: 'https://api.example.com',
+  transport: 'stdio',
+  port: 8080,
+  requestTimeout: 30000,
+  maxRetries: 0,
+  cacheTtlMs: 0,
+  analyticsEnabled: false,
+  sqsRegion: 'us-east-1',
+  oauthEnabled: false,
+  supabaseUrl: '',
+  supabaseOAuthClientId: '',
+  supabaseOAuthClientSecret: '',
+  supabaseServiceRoleKey: '',
+  mcpBaseUrl: '',
+  oauthAllowedRedirectUriPatterns: [],
+};
+
+// Every register function used by src/index.ts. registerAgentTools registers
+// two tools (browserless_skill + browserless_agent); the rest register one.
+const registrars = [
+  registerSmartScraperTool,
+  registerFunctionTool,
+  registerDownloadTool,
+  registerExportTool,
+  registerAgentTools,
+  registerSearchTool,
+  registerMapTool,
+  registerCrawlTool,
+  registerPerformanceTool,
+];
+
+// MCP clients (notably OpenAI) reject any tool that does not set all three
+// behavioural hints to an explicit boolean. fastmcp forwards `annotations`
+// verbatim into tools/list, so the hint must live on every tool's annotations.
+const REQUIRED_HINTS = [
+  'readOnlyHint',
+  'destructiveHint',
+  'openWorldHint',
+] as const;
+
+describe('tool annotations', () => {
+  afterEach(() => sinon.restore());
+
+  it('every registered tool sets all three behavioural hints as booleans', () => {
+    const server = new FastMCP({ name: 'test', version: '0.1.0' });
+    const addToolSpy = sinon.spy(server, 'addTool');
+
+    registrars.forEach((register) => register(server, mockConfig));
+
+    expect(addToolSpy.callCount).to.be.greaterThan(0);
+
+    addToolSpy.getCalls().forEach((call) => {
+      const tool = call.args[0];
+      const annotations = tool.annotations ?? {};
+      REQUIRED_HINTS.forEach((hint) => {
+        expect(
+          annotations[hint],
+          `${tool.name} is missing ${hint} (must be an explicit boolean)`,
+        ).to.be.a('boolean');
+      });
+    });
+  });
+});