I can’t find “Unknown tool call” documented in our MCP articles. However, to make an MCP tool callable by an agent, all of the following must be true per our docs. Please verify each step:
The MCP server is added as an integration and its tools are discoverable after “Add Integration”/test connection. Confirm the tool appears in that listed set. (elevenlabs.io)
The MCP server is attached to the specific agent you’re testing. Tools are only available to agents the server is added to. (elevenlabs.io)
The tool is not disabled by approval settings. In Fine-Grained Tool Approval, ensure the tool is enabled (auto-approved or requires approval, but not disabled). (elevenlabs.io)
If the external MCP server’s tool manifest changed, re-test the integration so ElevenLabs refreshes the available tools (tools are defined by the external server and can change). (elevenlabs.io)
If you configure the agent via API, ensure the tool is present via prompt.tool_ids (legacy prompt.tools is deprecated). (elevenlabs.io)
Check the Call History page for the full failure reason and context while reproducing the issue. (help.elevenlabs.io)
If the tool shows up in the integration’s tool list and is enabled for the agent but calls still fail, please share a screenshot of:
The integration’s tool list showing the exact tool name as discovered by ElevenLabs
The agent’s Tool Approval settings for that tool
This will help confirm whether the agent is actually receiving that tool from the MCP integration. (elevenlabs.io)
tardy iris
pearl ginkgo