ForgeMesh Library MCP demonstrates solid tool definition quality with consistent naming patterns, complete input schemas for all 8 tools, and comprehensive descriptions. All tools follow verb_noun naming convention (search_*, get_*, browse_*, book_of_the_day). Tool descriptions are well-crafted and explain cost/payment requirements clearly. However, there are notable gaps: (1) NO output schemas are documented anywhere in the source code, the descriptions state what tools return but never provide JSON Schema for the response structure; (2) idempotentHint is set to false for read-only tools that should be true, suggesting misunderstanding of the annotation semantics; (3) parameter descriptions lack format guidance (e.g., 'query' in search_literature should specify length bounds, language, or query syntax rules); (4) no error handling guidance is visible, tools reference x402 payment failures and API errors but provide no recovery instructions; (5) pagination is mentioned in tool descriptions but not formally exposed as parameters (search_books and search_literature accept 'limit' but no offset/cursor/page parameter for iteration). The server uses proper toolAnnotations (readOnlyHint, destructiveHint, idempotentHint), which is modern and correct. All 8 tools have complete, well-formed inputSchemas with required field declarations. Descriptions average ~250 chars, within the 194-char baseline but on the longer side, they could be tightened. The server properly injects secrets via environment variables (WALLET_PRIVATE_KEY, BASE_RPC_URL) and does not expose them in parameters, following pattern:secret-injection.

• Document output schemas for all 8 tools as formal JSON Schema objects. For example, search_literature should return: {passages: [{text: string, title: string, author: string, chapter: integer, book_id: integer}], total: integer, search_query: string}. Include these in tool definitions or a separate schema reference.
• Correct idempotentHint to true for all read-only retrieval tools (search_literature, search_books, get_book_metadata, get_chapter, get_quotes, ask_book, browse_shelf). These tools are safe to retry and should advertise that.
• Add JSON Schema constraints (minimum, maximum) to numeric parameters. E.g., 'limit' in search_literature should have {type: 'integer', minimum: 1, maximum: 30}. This allows LLMs and clients to validate inputs before sending.
• Add an enum constraint to the 'book' parameter in ask_book. Convert the FLAGSHIP_BOOKS lookup table into an enum array in inputSchema so LLMs can discover valid book names and avoid hallucination.
• Add error handling guidance to tool descriptions. Include text like: 'Requires WALLET_PRIVATE_KEY env var and USDC balance on Base network. Returns error 'insufficient_balance' if payment fails, use a different wallet or request USDC on Base. Errors are idempotent and safe to retry.'
• Add pagination parameters (offset/page or cursor) to search_literature and search_books, or document a 'next_cursor' field in the response schema so agents can iterate through large result sets.
• For browse_shelf, either provide an enum of valid shelf names in inputSchema or add a 'list_shelves' discovery tool. The current approach (requiring an out-of-band HTTP call to a .txt file) is not accessible to the LLM.