OpenResearch MCP demonstrates solid definition quality across 22 tools. All tools have clear, descriptive names following verb_noun conventions (web_search, read_url, search_openalex, etc.). Descriptions are well-written and contextual (avg ~150 chars), explaining both what the tool does and when to use it. Tool annotations are properly defined (readOnlyHint=true across all tools, appropriately destructiveHint=false, idempotentHint set correctly). Input schemas are present for all tools with typed parameters (string, integer, enum). Output documentation is implicit through descriptions rather than explicit JSON Schema documentation. Error handling is minimal but reasonable given the read-only nature. The server's instructions in server.py provide excellent context, including a tool selection guide that compensates for individual tool gaps.

• Add explicit JSON Schema output schemas for all 22 tools. Document each response object's fields, types, and what they contain. Example: search_openalex should document that results contain 'title', 'authors', 'pub_date', 'id', 'doi', 'is_open_access'.
• For list-returning tools (search_*, web_search), document pagination behavior: does max_results enforce a hard cap, is there an offset parameter, what is the maximum page size, and how does an agent request the next page?
• Add error handling guidance to tool descriptions. Example for read_url: 'Returns an error if the URL is unreachable, returns 403 if access is denied, or returns a message if content is too large. Retry once; if still blocked, try web_search instead.'
• Standardize output field names across similar tools. If read_url returns 'text', read_pdf should also return 'text' (not 'content'). This reduces field mapping overhead for LLMs chaining tools.
• Document rate limits explicitly in tool descriptions. search_news states rate limiting; search_openalex mentions 'zero rate limiting', extend this to all tools that call external services.
• Add idempotencyKey or request deduplication strategy to tools that might be retried (search_*, get_*), especially those that mutate external state or trigger side effects (e.g., email sends via SEC lookups).
• Consider adding optional 'raw_response' or 'debug' parameter to tools that call external APIs, allowing advanced users/agents to access unfiltered data when needed for troubleshooting.