Default to string for script tool arguments

Signed-off-by: David Gageot <david.gageot@docker.com>

Author: dgageot

pkg/tools/builtin/script_shell.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"maps"
 	"os"
 	"os/exec"
 	"slices"
@@ -110,7 +111,7 @@ func (t *ScriptShellTool) Tools(context.Context) ([]tools.Tool, error) {
 
 		inputSchema, err := tools.SchemaToMap(map[string]any{
 			"type":       "object",
-			"properties": cfg.Args,
+			"properties": defaultPropertyTypes(cfg.Args, "string"),
 			"required":   cfg.Required,
 		})
 		if err != nil {
@@ -158,3 +159,20 @@ func (t *ScriptShellTool) execute(ctx context.Context, toolConfig *latest.Script
 
 	return tools.ResultSuccess(limitOutput(string(output))), nil
 }
+
+// defaultPropertyTypes returns a copy of properties where any property
+// missing a "type" field gets the given default type.
+func defaultPropertyTypes(properties map[string]any, defaultType string) map[string]any {
+	result := make(map[string]any, len(properties))
+	for k, v := range properties {
+		if prop, ok := v.(map[string]any); ok && prop["type"] == nil {
+			propCopy := make(map[string]any, len(prop)+1)
+			maps.Copy(propCopy, prop)
+			propCopy["type"] = defaultType
+			result[k] = propCopy
+			continue
+		}
+		result[k] = v
+	}
+	return result
+}

pkg/tools/builtin/script_shell_test.go

@@ -115,3 +115,38 @@ func TestNewScriptShellTool_MissingRequired(t *testing.T) {
 	require.Nil(t, tool)
 	require.ErrorContains(t, err, "tool 'docker_images' has required arg 'img' which is not defined in args")
 }
+
+func TestNewScriptShellTool_ArgWithoutType(t *testing.T) {
+	shellTools := map[string]latest.ScriptShellToolConfig{
+		"greet": {
+			Description: "Greet someone",
+			Cmd:         "echo Hello $name",
+			Args: map[string]any{
+				"name": map[string]any{
+					"description": "Name to greet",
+				},
+			},
+			Required: []string{"name"},
+		},
+	}
+
+	tool, err := NewScriptShellTool(shellTools, nil)
+	require.NoError(t, err)
+
+	allTools, err := tool.Tools(t.Context())
+	require.NoError(t, err)
+	assert.Len(t, allTools, 1)
+
+	schema, err := json.Marshal(allTools[0].Parameters)
+	require.NoError(t, err)
+	assert.JSONEq(t, `{
+	"type": "object",
+	"properties": {
+		"name": {
+			"description": "Name to greet",
+			"type": "string"
+		}
+	},
+	"required": ["name"]
+}`, string(schema))
+}