This server exposes 20 financial data tools via the Yahoo Finance API. While all tools follow a consistent naming pattern (get_*) and have basic descriptions, the schema and parameter definition quality is mediocre. Most tools accept only a 'symbols' parameter (comma-separated string) with minimal validation, lack output schema documentation, and have descriptions that are functional but lack LLM-optimization guidance. Tools like get_balance_sheet and get_cash_flow include a 'frequency' parameter with a default, but parameter descriptions are brief (under 50 chars). No tools document their return structure, which violates the pattern:tool requirement. Error handling is minimal, the code wraps external API calls with generic try/catch and format_response(), offering no actionable recovery guidance. The server demonstrates basic competence but falls short of production-grade agent tool design.

• Document output schemas for every tool. Example: 'Returns a JSON object with keys: symbol (str), marketCap (float), peRatio (float), dividend (float), ...' This allows LLMs to understand result structure before calling the tool.
• Add enum constraints to 'frequency' parameters. Change from free-form string to enum: ['annual', 'quarterly']. This prevents invalid values and is machine-parseable.
• Expand parameter descriptions to 100-150 characters. Current descriptions like 'Comma-separated list of stock symbols' do not explain valid formats (UPPERCASE?, length limits?, max count?). Add: 'Comma-separated list of valid stock symbols in UPPERCASE (e.g., AAPL,MSFT,GOOGL). Max 20 symbols per call. Invalid symbols are silently ignored.'
• Implement structured error handling. Catch yahooquery exceptions separately: If SymbolNotFound → return 'Invalid symbol: INVALID. Valid US stock symbols are uppercase letters only. Search for the correct ticker before retrying.' If RateLimited → return 'Rate limited. Retry in 60 seconds.' If NetworkError → return 'Network error. This is retryable.'
• Add pagination support to tools returning lists. Accept limit (default 20, max 100) and offset parameters. Return { results: [...], total_count: N, has_more: bool } structure so agents can fetch batches without overloading the context window.
• Expand tool descriptions to distinguish overlapping tools. Example: 'get_financial_data: Key financial metrics (cash, debt, revenue) for comparison and analysis. Use this for balance sheet ratios. get_summary_detail: Current stock price, trading volume, and market cap. Use this for quick price checks or watchlist building.' This guides LLM selection.