Two read-only search/retrieval tools with well-structured schemas and descriptions. Both tools have action-verb names, documented input parameters with type constraints (enums, defaults, limits), and clear non-destructive semantics. Description lengths are adequate (150-180 chars). Input schemas are comprehensive with constraints like min_length, minimum, maximum, enum values. Output types are documented in code (SearchLibraryOutput, NormalizedRecord). However, output schema details are not fully visible in the provided excerpt, limiting certainty on field documentation. No tool annotations (readOnlyHint/idempotentHint) present in code. Error handling via ToolError union type suggests some error structure, but recovery guidance is not explicit in descriptions. Overall solid for a read-only service but lacks refinements expected of A-grade tools.

• Add explicit field-level documentation for SearchLibraryOutput and NormalizedRecord. Include in the tool description or a separate schema document which fields are present, their types, and whether they are always populated or may be null/absent. Specifically document availability, metadata, location, and link fields.
• Declare tool annotations: both tools should include readOnlyHint=true and idempotentHint=true in their registration. In FastMCP, this may be added via @mcp.tool() decorator metadata or tool registration parameters.
• Enhance error recovery guidance in tool descriptions. Add sentences like: 'If record not found, the result will have an error field; try search_library() to discover the correct record ID. If search returns no results, try broader keywords or different search fields (title, author, subject).'
• For search_library's 'filters' object parameter, formally define the valid values for resourceType (array of enum strings like ['books', 'articles', 'journals', ...]) and availability (array of enum strings like ['available', 'unavailable', 'on_order', ...]). If these are dynamic or open-ended, state so explicitly and provide an example list.
• Add a note in the 'include_availability' parameter description stating that setting it to false may improve response latency for large result sets.
• Consider adding a 'best_match' field to SearchLibraryOutput results to indicate the top result, helping LLMs quickly identify the most relevant item without parsing ranked lists.