MCP-Warden exposes 9 browser automation tools with basic schemas and descriptions. All tools have descriptions (10-50 chars, below the 50-200 char optimum), and input schemas are present but minimal. Parameters lack detailed constraints, enums, and format guidance. No output schemas documented. Error handling is absent, no recovery guidance, retryability classification, or actionable error messages. Tool naming follows verb_noun convention (browser_*) but descriptions are generic and do not explain WHEN to use each tool or what distinguishes similar operations (e.g., browser_click vs browser_type). No tool annotations (readOnlyHint, destructiveHint, idempotentHint). Security: tools accept element selectors and filenames as parameters without visible input validation or sanitization. No audit logging or permission gates visible in provided code. Composition: tools are single-purpose but lack chaining metadata (e.g., browser_click does not document what state it leaves for browser_wait_for). Overall: functional but well below production baseline for agent-facing tools.

• Add output schemas to all tools. Example: browser_navigate should return {success: boolean, url: string, title: string, error?: string}. browser_click should return {success: boolean, elementFound: boolean, error?: string}.
• Expand descriptions to 50 - 200 characters with WHEN/WHY guidance. Example: 'Navigate to a URL. Use this to load a new page or refresh. Returns success status and page title. Fails if URL is invalid or network is unreachable.'
• Add tool annotations: mark browser_navigate, browser_go_back, browser_wait_for as readOnlyHint=true (safe to retry); mark browser_click, browser_type, browser_select_option as destructiveHint=true (may have side effects).
• Document the 'ref' parameter: 'Reference identifier for the target element, obtained from a prior browser_snapshot or browser_take_screenshot call.' Add enum or pattern constraint for 'key' in browser_press_key: 'Valid keys: Enter, Escape, Tab, ArrowUp, ArrowDown, etc.'
• Implement error responses with recovery guidance. Example: 'Invalid URL: got "example". Must start with http:// or https://. Retry with a valid URL.' Classify errors as retryable (network timeout) vs user-fixable (invalid selector) vs fatal (browser crashed).

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry