Three well-defined tools with solid schemas and descriptions. All tools have clear action verbs and parameters are properly typed with enums where appropriate. Descriptions are moderately detailed (150-250 chars) but lack actionable error recovery guidance. No tool annotations (readOnlyHint, destructiveHint). Output schemas are not explicitly documented in the code; responses are raw JSON stringified. Error handling is minimal, no guidance for LLM recovery or retry paths. Tool names follow verb_noun pattern correctly. Parameter validation is present via Zod but error messages are not exposed to the LLM.

• Add explicit output schema documentation. Define a TypeScript interface for ArticleResult (title, description, source, author, url, imageUrl, publishedAt, content) and include it in JSDoc or a separate schema file. Make it clear what fields LLMs can expect and use in downstream calls.
• Declare tool annotations in the server.tool() registration: add a 'readOnlyHint' property set to true for all three tools. Example: server.tool('searchArticles', ..., { readOnlyHint: true }).
• Enhance error handling: wrap API calls and validation in try-catch with actionable error messages. Instead of throwing raw Zod errors, catch them and return a tool response with error content: { type: 'text', text: 'Invalid searchIn field: got "author", must be one of: title, description, content' }.
• Update tool descriptions to include result volume expectations and pagination strategy. Example: 'Returns up to 100 articles per page (default 20). Use the page parameter to iterate through results. Call getSources first to discover valid source identifiers.'
• Add a discovery hint to searchArticles and getTopHeadlines: 'To find valid source IDs, call getSources first with your desired category and language.'
• Document the NewsAPI rate limits (if any) in the server initialization or tool descriptions, and add request throttling if rate limits are tight.
• Consider adding a 'getSources' discovery tool description enhancement: 'Returns a list of all available news sources. Use source IDs returned here in searchArticles or getTopHeadlines source parameter.'