{
  "result": {
    "content": [
      {
        "type": "text",
        "text": "fictional fixture response"
      }
    ]
  },
  "meta": {
    "tool": "fixture.echo",
    "provider": "Fixture Provider",
    "cost_cents": 1,
    "cost": "$0.0100",
    "latency_ms": 12,
    "remaining_balance_cents": 499
  }
}