Constant FOCUS_WINDOW_TOOL 

pub(crate) const FOCUS_WINDOW_TOOL: &str = r#"{
  "name": "FocusWindow",
  "description": "Bring an AgentMux window to the foreground. Defaults to your own window. Pass window_id (from Layout(query:\"windows\") or Layout(query:\"layout\")) to focus a specific one.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "window_id": { "type": "string", "description": "Optional window to focus; defaults to your own" }
    }
  }
}"#;