Single tool with minimal definition quality. Tool name 'search_by_keyword' is acceptable but description is critically sparse (7 chars: 'search'). Input schema is present with proper types (string, array) and some parameter descriptions, but descriptions are generic and lack actionable guidance. No output schema documented. No error handling guidance. Tool performs web scraping with no validation, rate limiting, or recovery hints. Fails multiple critical checks from the rubric.

• Expand tool description to 50-200 characters explaining: (1) searches Booth.pm for 3D products by keyword, (2) when to use it (user wants to find specific items), (3) what it returns (array of products with name, price, shop, URL). Example: 'Search Booth.pm for 3D models, characters, and assets by keyword. Returns product details including name, price, shop name, and direct URL. Use this to find specific items or browse categories.'
• Document the output schema explicitly in code comments or a separate schema definition. Specify that the response is an array of BoothProduct objects with fields: id (string), name (string), price (string), shopName (string), shopDisplayName (string), category (string), categoryName (string), url (string), thumbnailUrl (string). Include field descriptions and nullability.
• Add parameter descriptions with format constraints: keyword should be 1-100 characters (no special chars); exceptWords should be an array of 0-10 strings, each 1-50 chars; tags should be an array of valid Booth.pm category tags (enumerate or link to docs). Example: 'keyword: Search term (1-100 chars, e.g. "VRChat avatar"). Spaces separate multiple terms.'
• Implement result limiting and pagination. Cap results at 20-50 products per call. Add optional limit and offset/page parameters. Return total_count and next_cursor in response. Document in description: 'Returns up to 20 results per page. Use offset parameter to paginate through larger result sets.'
• Add error handling with recovery guidance. Catch network errors, timeouts, and parsing failures. Return structured error responses: {type: 'network_error', message: 'Booth.pm is unreachable. Try again in a few seconds.', retryable: true} instead of raw error objects. Guide LLM on retry strategy.