Two tools with basic schemas and descriptions, but significant gaps in parameter documentation, error handling, and output structure. search_papers has a WRITE risk but no confirmation pattern. extract_info returns unstructured strings instead of typed objects. Both tools lack actionable error messages and recovery guidance. Naming is clear (verb_noun), but descriptions are generic and under-optimized for LLM selection. No tool annotations (readOnlyHint, destructiveHint). Output schemas are not documented.

• Add output schema documentation for both tools. search_papers should document it returns List[str] (paper IDs); extract_info should return {title: str, authors: str[], summary: str, pdf_url: str, published: str} as a typed object, not a JSON string.
• Expand tool descriptions to 150-250 chars. For search_papers: 'Search arXiv for papers on a topic and cache results locally. Use this to discover papers; then call extract_info to retrieve cached details. Creates a topic folder and stores paper metadata as JSON.' For extract_info: 'Retrieve cached paper details by ID from previously searched topics. Returns structured paper metadata (title, authors, summary, URL, date). Call search_papers first if the paper is not cached.'
• Add destructiveHint=true to search_papers (modifies filesystem) and readOnlyHint=true to extract_info. Register tools with explicit annotations in FastMCP decorator.
• Implement structured error responses. Instead of returning bare strings, return {success: bool, data?: object, error?: {code: str, message: str, recovery_hint: str}}. E.g., extract_info not found: {success: false, error: {code: 'PAPER_NOT_FOUND', message: 'Paper ABC123 not found in cache', recovery_hint: 'Call search_papers(topic=...) to search and cache papers first.'}}
• Add max_results validation and document constraints. search_papers should validate max_results is 1-100 and return clear error if violated. Document in parameter description: 'Maximum number of results (1-100, default 5). Larger values increase API latency.'