Financial News MCP has clear, well-structured tool definitions with proper schemas and descriptions. All 4 tools are explicitly registered with inputSchema, descriptions, and parameter constraints (enums, min/max). Naming follows verb_noun convention (get_*, search_*, list_). However, output schemas are not documented, responses are formatted as plain text rather than structured objects, limiting downstream tool chaining. Parameter descriptions are adequate but lack dependency hints and format guidance. No error handling guidance for invalid sources or network failures. No tool annotations (readOnlyHint, etc.) despite all tools being read-only.

• Convert text output to structured JSON objects. Return articles as {title, url, source, published, summary, category} arrays so LLMs can extract and chain specific fields.
• Add readOnlyHint: true to all tool definitions in list_tools() to signal immutability and enable client-side caching.
• Document output schema in tool descriptions: 'Returns a list of articles with fields: title (string), url (string), source (string), published (ISO 8601 date), summary (string).'
• Add error recovery guidance: 'If source is invalid, call list_news_sources() to see available options.' Include this in get_news_by_source description.
• Add length and format constraints to search query: 'query (string, 1-200 characters, alphanumeric + spaces/hyphens). Examples: "Apple earnings", "Fed interest rates".' Use description text since LLMs ignore JSON Schema pattern fields.