{
  "$comment": "Sample error response for estimate_fare when the pickup address cannot be geocoded. isError=true is set inside result per the MCP tool-error convention (not a JSON-RPC transport error).",
  "request": {
    "jsonrpc": "2.0",
    "id": 2,
    "method": "tools/call",
    "params": {
      "name": "estimate_fare",
      "arguments": {
        "pickup": "xxx",
        "dropoff": "Glasgow Airport",
        "vehicleType": "saloon"
      }
    }
  },
  "response": {
    "jsonrpc": "2.0",
    "id": 2,
    "result": {
      "isError": true,
      "content": [
        {
          "type": "text",
          "text": "Could not estimate fare — address could not be geocoded or the routing service is unavailable."
        }
      ]
    }
  }
}