curl 'https://api.gumloop.com/api/v1/mcp/tools/call' \
  -H 'Authorization: Bearer YOUR_ACCESS_TOKEN' \
  -H 'Content-Type: application/json' \
  -d '{
    "team_id": "team_4f8c92ab",
    "calls": [
      {
        "ref": "send-1",
        "server_id": "gumloop_slack",
        "tool_name": "slack_send_message",
        "arguments": {"channel": "#general", "text": "Hello from Gumloop"}
      }
    ]
  }'

{
  "results": [
    {
      "ref": "send-1",
      "server_id": "gumloop_slack",
      "tool_name": "slack_send_message",
      "status": "success",
      "content": [
        {
          "type": "text",
          "text": "Message sent to #general"
        }
      ],
      "error": null
    }
  ]
}