Skip to main content

Documentation Index

Fetch the complete documentation index at: https://docs.narrative.io/llms.txt

Use this file to discover all available pages before exploring further.

HTTP status: 400

​
Error message

tool_choice references unknown tool name '{name}' — not found in the catalog

​
When this error occurs

tool_choice: { kind: "specific_tool", ... } pins the model to a single tool on iteration 1 of the run. The platform validates that the named tool exists in the effective catalog before kicking off the workflow — better to fail synchronously here than later as a confusing Bedrock-side error inside the agent loop. This error surfaces when either:
  • mcp_alias is absent and name doesn’t appear in caller-declared tools[].
  • mcp_alias is present (and the alias is registered), but name doesn’t appear in that MCP server’s declared tools[].

​
How to fix

Make sure tool_choice.name matches the catalog exactly: 
// Caller-declared target
{ "kind": "specific_tool", "name": "confirm_booking" }

// MCP-pinned target
{ "kind": "specific_tool", "mcp_alias": "docs", "name": "search_kb" }
If you only know the wire form (docs-search_kb), split it: prefix before the first dash becomes mcp_alias, suffix becomes name.