Constant PTY_SHELL_INPUT_TOOL 

pub(crate) const PTY_SHELL_INPUT_TOOL: &str = r#"{
  "name": "PtyShellInput",
  "description": "Write raw text to a PtyShell()'s PTY, as if typed at a keyboard. Unlike ShellInput, no newline is appended — send exactly what a keypress would produce (e.g. \"y\\n\" to answer a prompt and press Enter, or \"\\u0003\" for Ctrl+C — the OS PTY layer delivers that as a real interrupt to the foreground process, same as a human pressing Ctrl+C, without ending the shell).",
  "inputSchema": {
    "type": "object",
    "properties": {
      "shell_id": { "type": "string", "description": "The shell_id returned by a prior PtyShell() call" },
      "text":     { "type": "string", "description": "Raw text to write — no newline is added automatically" }
    },
    "required": ["shell_id", "text"]
  }
}"#;