Arc CDP MCP has 11 well-structured tools with consistent naming (arc_* prefix) and mostly complete schemas using Zod. Descriptions are present and contextual (Portuguese, appropriate for the domain). However, several tools lack parameter descriptions, output schemas are not formally documented, and error handling is minimal. Tool composition is sound (each does one thing), but parameter validation and recovery guidance are weak. Average tool score: 62/100.

• Document output schemas for all tools. E.g., arc_read_page returns {title, url, text, elements: [{ref, tag, type, name, href}]}. This enables LLM planning and tool chaining.
• Enhance error messages with recovery guidance. E.g., 'Element not found. Try arc_read_page() to see available elements and their refs.' or 'Navigation timeout. Check network via arc_network() or retry with longer timeout.'
• Add input validation to arc_eval: reject expressions containing 'fetch', 'XMLHttpRequest', or 'localStorage' to prevent data exfiltration. Return 'Blocked: expression contains restricted API' with allowed alternatives.
• Implement optional dry-run mode for destructive tools (arc_close_tab, arc_click with form submission). Add dryRun boolean parameter; when true, return what would happen without executing.
• Strengthen locate() validation: require at least one of {ref, selector, text}; return 'Missing target: provide ref (preferred), selector, or text' if all are omitted. Add timeout parameter to arc_click and arc_type for better control.