Single tool with basic schema and description. Tool name follows verb_noun pattern (get-stock-data). Description is adequate at 56 chars but lacks context on when to use vs alternatives, prerequisites, or return structure. Input schema present with type and description for symbol parameter, but no enum constraints, format validation, or range limits. No output schema documented. Error handling returns text but lacks actionable recovery guidance. No pagination, no result limits stated, no chaining IDs. Composition is simple (one tool, one job) but incomplete for production use.

• Document output schema: {symbol: string, lastUpdated: ISO8601, dailyPrices: [{date, open, high, low, close, volume}]}. This enables LLMs to chain calls and extract specific fields.
• Add enum or regex constraint to symbol parameter: 'Stock symbol: 1-5 uppercase letters (e.g., AAPL, MSFT). Use search_symbols() if unsure.'
• Expand tool description to 100-150 chars: 'Fetch last 5 trading days of OHLCV data for a stock symbol. Returns formatted text with open, high, low, close prices and volume. Call search_symbols() first if you only have a company name.'
• Replace generic error messages with actionable guidance: 'Symbol not found: INVALID. Valid symbols are 1-5 uppercase letters. Try search_symbols("company name") to find the correct symbol.'
• Remove hardcoded API key from source. Use dotenv only; fail fast if ALPHA_VANTAGE_API_KEY is missing. Never commit secrets to repo.