The server defines 3 stock analysis tools with clear action verbs and reasonable descriptions. However, significant gaps exist: parameter descriptions are minimal, output schemas are completely undocumented, error handling provides no recovery guidance, and the implementation returns raw string responses rather than structured JSON despite claiming json_response=True. Tools are read-only (low risk), but descriptions lack LLM-optimized clarity and parameter constraints. The codebase shows basic tool registration via FastMCP but lacks the structured output and error guidance patterns expected of production-grade tools.

• Convert all tool outputs from strings to structured JSON objects. Example: get_stock_price should return {ticker, price, currency, timestamp} instead of 'AAPL 目前價格為 150.25 USD'. This enables downstream tool chaining and field extraction.
• Add comprehensive parameter descriptions with format, range, and constraint rules. For 'ticker': 'Stock ticker symbol (e.g., AAPL for US stocks, 2330.TW for Taiwan). Format: 1-10 uppercase letters with optional .XX country suffix.'
• Enhance error messages with actionable recovery guidance. Replace 'Unable to get TICKER: ...' with 'Ticker TICKER not found. Valid formats: AAPL (US), 2330.TW (Taiwan). Try searching for a similar ticker with search_tickers().'
• Add explicit output schema documentation. Document return type for each tool. Example: '{ticker: string, price: number, currency: string, last_updated: ISO8601 timestamp}'
• For get_valuation_analysis, split large responses into separate tools or add a mode parameter (e.g., mode=summary|detailed) with explicit limits on response length.
• Add parameter validation with clear error messages. Example: if ticker is empty or longer than 10 chars, return 'Invalid ticker: must be 1-10 characters (e.g., AAPL, 2330.TW)'
• Document which parameters are optional vs required. All three tools currently accept only a required 'ticker', clarify this in descriptions.