{
  "$comment": "Sample error response for start_booking when passenger count exceeds vehicle capacity. Capacity is validated before geocoding so this returns quickly.",
  "request": {
    "jsonrpc": "2.0",
    "id": 4,
    "method": "tools/call",
    "params": {
      "name": "start_booking",
      "arguments": {
        "pickup": "Helensburgh Central Station",
        "dropoff": "Glasgow Airport",
        "vehicleType": "saloon",
        "passengers": 6
      }
    }
  },
  "response": {
    "jsonrpc": "2.0",
    "id": 4,
    "result": {
      "isError": true,
      "content": [
        {
          "type": "text",
          "text": "Vehicle 'saloon' seats up to 4 passengers, but 6 were requested. Choose 'mpv' for groups over 4."
        }
      ]
    }
  }
}