18 tools with complete input schemas and descriptions, but significant quality gaps. Naming is verb-forward (browser_*, run_*, etc.) and mostly clear. Descriptions average ~60 chars, below the 194-char baseline, and lack context on WHEN to use tools or what they return. No output schemas documented. Parameter descriptions are minimal; many lack format/constraint guidance. Error handling is absent, no recovery guidance, no categorization of retryable vs fatal errors. Security concerns: run_command accepts arbitrary shell commands with no sanitization or permission gates. keystroke and click_at require Accessibility permission but don't document this prerequisite clearly. No audit logging or rate limiting visible. Tools like browser_evaluate expose arbitrary JavaScript execution without sandboxing. Composition is reasonable (single responsibility per tool), but chaining is weak, no documented output fields to support downstream tool calls.

• Add output schemas to every tool. Document the structure, field types, and any truncation/pagination. E.g., browser_tabs should return [{index: number, url: string, title: string}]; browser_read should return {text: string, truncated: boolean, length: number}.
• Expand descriptions to 100 - 200 chars. Include WHEN to use the tool, prerequisites, and what it returns. E.g., keystroke: 'Send keystrokes to the frontmost app (requires Accessibility permission on macOS). Returns success or error. Use for keyboard shortcuts, text input, or navigation when browser_type is not applicable.'
• Implement input validation and sanitization for run_command. Reject dangerous patterns (rm, kill, sudo, etc.) or require explicit confirmation. Add a dry_run parameter to preview commands before execution. Log all command invocations with timestamp and result.
• Add permission gates and audit logging. keystroke and click_at should check Accessibility permission and log who called them. run_command should require explicit user confirmation for destructive operations. All tools should emit structured logs (timestamp, tool, params, result, user/agent ID).
• Implement error recovery guidance. Catch common failures (element not found, timeout, permission denied) and return actionable messages. E.g., 'CSS selector not found. Try browser_screenshot() to see current page state, then adjust selector.' Categorize errors as retryable (timeout, network) vs user-fixable (invalid selector) vs fatal (permission denied).