This MCP server has foundational weaknesses that prevent it from being production-ready. Both tools have descriptions and basic parameter structure, but lack critical rigor: (1) no parameter type information visible in the schema definitions, the input specs show only description and required fields, missing 'type' declarations; (2) output schemas are not documented, responses are inferred from return values (json!({ "app": ..., "closed": true })) but no formal schema is provided to the LLM; (3) error handling is minimal, close_app checks for protected processes but provides no recovery guidance; (4) the schema for list_apps parameter 'app' has no type field visible, violating JSON Schema basics; (5) no tool annotations (readOnlyHint, destructiveHint) despite close_app being IRREVERSIBLE. The codebase is well-structured (Rust, modular, good linting), but the MCP tool definitions themselves lack the rigor expected of production tools.

• Add explicit 'type' field to all input parameters. Example: { "app": { "type": "string", "description": "Optional application name to filter by", "required": false } }.
• Document output schema for both tools. Define the structure: list_apps returns { "apps": [{ "name": string, "pid": integer, "bundle_id": string|null }] }, close_app returns { "app": string, "closed": boolean }.
• Expand tool descriptions to 100 - 200 characters each. Include WHEN to use and WHAT is returned. Example: 'List running applications on the system. Optionally filter by name (case-insensitive). Returns app name, process ID, and bundle ID. Call this first to discover available apps before closing them.'
• Add tool annotations to the tool definition (if not visible in code excerpt, add to registration). Mark list_apps with readOnlyHint=true and close_app with destructiveHint=true.
• Enhance error handling for close_app to include recovery hints. When a protected process is rejected, suggest: 'The application '{app}' is a system process and cannot be closed. Use list_apps to find user applications, or check if '{app}' is actually a protected process.'
• Add result limits and pagination guidance to list_apps description: 'Returns up to 100 applications. If you need to process many apps, use the app filter parameter to narrow the list by name.'
• Consider adding a dry-run parameter or confirmation pattern for close_app to prevent accidental termination. Example: add force_close parameter with clear warning, or return a confirmation code the agent must acknowledge before executing the actual close.