[
  {
    "agent_name": "root",
    "timestamp": "<ts>",
    "type": "tool_call",
    "tool_call": {
      "id": "<call-id>",
      "type": "function",
      "function": {
        "name": "handoff",
        "arguments": "{\"agent\": \"reviewer\"}"
      }
    },
    "tool_definition": {
      "name": "handoff",
      "category": "handoff",
      "description": "Use this function to hand off the conversation to the selected agent.",
      "parameters": {
        "additionalProperties": false,
        "properties": {
          "agent": {
            "description": "The name of the agent to hand off the conversation to.",
            "type": "string"
          }
        },
        "required": [
          "agent"
        ],
        "type": "object"
      },
      "annotations": {
        "idempotentHint": false,
        "readOnlyHint": true,
        "title": "Handoff Conversation"
      },
      "outputSchema": null
    }
  }
]