Constant SHELL_STOP_TOOL 

pub(crate) const SHELL_STOP_TOOL: &str = r#"{
  "name": "ShellStop",
  "description": "Stop a running shell started by Shell(). Pass the shell_id returned by Shell. Tree-kills the whole process group (e.g. `task dev` and its child task.exe/node processes), so prefer this over kill/taskkill — those can hit other agents' or the host's processes by name.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "shell_id": { "type": "string", "description": "The shell_id returned by a prior Shell() call" }
    },
    "required": ["shell_id"]
  }
}"#;