How do you force Claude to use a specific tool?

Tool Choice Configuration

{
  "model": "claude-3-5-sonnet-20241022",
  "max_tokens": 1024,
  "tools": [
    {
      "name": "fetch_user_records",
      "description": "Retrieves user files.",
      "input_schema": {
        "type": "object",
        "properties": {
          "user_id": { "type": "string" }
        },
        "required": ["user_id"]
      }
    }
  ],
  "tool_choice": {
    "type": "tool",
    "name": "fetch_user_records"
  },
  "messages": [
    { "role": "user", "content": "Help me lookup account 987." }
  ]
}