Arxiv Searcher has 4 tools with mixed definition quality. All tools have descriptions (50-150 chars each), which is adequate but brief. All tools have input schemas with type definitions and parameter descriptions. However, schemas lack output schema documentation, the rubric baseline shows 100% of A+ tools have documented return types. Parameter naming follows verb_noun conventions well (search_papers, get_paper_details, download_paper, analyze_trends). Tool names are action-oriented and clear. The main deficits are: (1) no documented output schemas visible in the code, (2) missing enum constraints on 'category' parameter despite being a known set of arXiv categories (defaults to 'cs.SE' but doesn't enumerate valid options), (3) no error handling guidance in tool descriptions (e.g., what happens if arxiv_id is invalid, or if PDF download fails), (4) no per-field output documentation. The 'category' parameter accepts a string with a default but no validation or enum list, inviting hallucinated category names. Average per-tool score: 58/100.

• Add explicit output schemas to all 4 tools. For example, search_papers should document: { papers: [{ arxiv_id: string, title: string, authors: [string], published: string, summary: string }], total_count: integer }.
• Convert the 'category' parameter to an enum. Extract valid arXiv categories from arxiv_categories.json and include them in the parameter definition: enum: ['cs.AI', 'cs.CL', 'cs.SE', 'cs.LG', ...]. This prevents hallucinated categories.
• Expand tool descriptions to 150-250 characters. Include WHEN to use each tool and how they differ. Example for search_papers: 'Search arXiv for papers matching natural language queries. Use when looking for specific papers by keyword, author, or date. Returns up to max_results papers with metadata needed for download or analysis. For trend analysis across many papers, use analyze_trends instead.'
• Add error handling guidance to each tool description. Example: 'If search returns 0 papers, try: (1) removing year filters, (2) broadening keywords, (3) searching in a broader category. If arxiv_id is invalid, search_papers can help find the correct ID.'
• Document download_paper return value and edge cases. Specify: 'Returns the local filepath where the PDF was saved. Fails if: arXiv ID is invalid, PDF exceeds [X] MB, or disk space is unavailable. On failure, the error message suggests recovery steps (e.g., check arxiv_id with get_paper_details).'
• Add result limits and pagination guidance to search_papers and analyze_trends. Document: 'Results are capped at 100 to prevent timeout. For comprehensive searches, call multiple times with different date ranges or categories. Results include a total_count field; use offset/pagination to fetch next batch.'

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

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