The server defines 4 tools with basic schemas and descriptions. All tools have descriptions and registered input schemas using Zod, which is positive. However, schemas are minimal (most tools have 1-2 parameters), descriptions are brief and lack actionable context for LLM selection, and there is no documented output schema. Parameter descriptions contain example values (a documented anti-pattern) rather than formal constraints. Error handling is present but provides generic responses without recovery guidance. The tool set is well-named (verb_noun pattern) and addresses a coherent domain (book preferences), but lacks depth in design patterns like idempotence, pagination, and chaining. Tool output is unstructured text rather than typed JSON, forcing LLMs to parse freeform responses.

• Define typed output schemas for all tools. Return structured objects: getProfile should return {userName, favoriteGenres: string[], favoriteAuthors: string[], booksRead: {title: string, author: string, dateAdded: string}[], dislikedBooks: ..., dislikedAuthors: string[]}. This lets LLMs reliably extract and chain data.
• Replace example values in descriptions with formal enums or patterns. Example: 'genre: An enum value, see available genres via list_genres() tool' or 'genre: A string matching pattern ^[a-z\s]+$ (lowercase letters and spaces only)'.
• Expand tool descriptions to 100-150 characters with WHEN and WHAT context. Example: 'Retrieve your reading profile (genres, authors, books read, dislikes). Use this first to see your preferences before adding new entries.' This helps LLMs decide when to invoke.
• Document pagination for getProfile. Add optional parameters (limit: 20, offset: 0) and return total counts for each array. State in description: 'Retrieves last 20 genres, 20 authors, 20 books read (paginated).'
• Add idempotence documentation and enforcement to addBookRead. Document: 'Idempotent: calling with the same title+author twice results in one entry (no duplicates).' Implement a check similar to addGenre.
• Categorize errors with recovery guidance. Instead of generic catch, return: {status: 'error', code: 'DUPLICATE_GENRE', message: 'Genre already added', recoveryAction: 'Call getProfile to see existing genres'}.
• Add a list_genres (or similar discovery tool) to help agents understand valid options without trial-and-error. Return available/popular genres so agents can suggest them to users.