MCP Tool Definition Not Found

Support Help
1

Anyone have any issues with MCP Tool Definition Not Found? It could not be more clearly set, but I keep getting this error, and wonder if anyone has any troubleshooting steps

2

Based on the available sources, here are troubleshooting steps for MCP tool detection issues:

Common Causes:

The MCP server connectivity is typically the root cause(1). Check these areas:

  1. Verify MCP Server Status

    • Ensure your MCP server is actually running and responding(1)
    • The server might appear up but not properly expose the tools(1)

  2. Check Server Logs

    • Review MCP server logs for errors that aren’t showing in the UI(1)
    • Authentication or configuration issues often appear here(1)

  3. Restart Connection

    • Try disconnecting and reconnecting the MCP server completely(1)
    • This resolves many tool discovery failures(1)

Configuration Steps:

When setting up MCP in Retell AI(2):

  • Add MCP configuration with proper authentication(2)
  • Set request headers if needed(2)
  • Configure query parameters if required(2)
  • Select the MCP tool from available tools(2)
  • Update your prompt to explicitly state when to invoke the tool(2)

API Verification:

You can verify available tools using the Get MCP Tools endpoint(3):

import Retell from 'retell-sdk';
const client = new Retell({
 apiKey: 'YOUR_RETELL_API_KEY',
});
const mcpToolDefinitions = await client.mcpTool.getMcpTools('oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD', {
 mcp_id: 'mcp-server-1',
});
console.log(mcpToolDefinitions);

(3)

The issue is usually an MCP server configuration or authentication problem rather than a Retell AI platform issue(1).