Single tool 'search_articles' has a well-structured schema with 11 parameters, all typed and described. Naming follows verb_noun convention (search_articles). Description is 194 chars, explaining semantic search, filters, and default behavior. However, output schema is not documented, the response structure is not visible in the source. Parameter descriptions are adequate but lack format constraints (e.g., date_from/date_to state 'YYYY-MM-DD format' but no regex or validation guidance). No error handling guidance is visible. The tool is read-only (good), but lacks idempotent/destructive annotations. Overall: solid foundation, but incomplete output documentation and missing error recovery patterns prevent a higher score.

• Document the output schema explicitly: list all fields returned (e.g., article_id, title, author, source, tags, rating, date_ingested, content_preview), their types, and whether results are paginated. Include a sample response.
• Add error handling guidance to the tool description: 'Returns empty list if no matches found. If filters are invalid (e.g., invalid date format), returns a 400 error with the constraint violated.'
• Convert parameter constraints to formal schema: add enum for ai_tier, ingestion_method; add pattern for date_from/date_to (^\d{4}-\d{2}-\d{2}$); add minimum/maximum for rating_min (-1 to 2).
• Declare tool annotations in the schema: add readOnlyHint=true and idempotentHint=true to signal that repeated calls are safe and cacheable.
• Clarify pagination: if max_results=20 is a hard cap, state 'Returns up to 20 results. For larger datasets, use date_from/date_to filters to narrow scope.' If pagination is supported, document cursor/offset mechanism.