Use this whenever the user asks about a specific public company or stock ticker in general: 'tell me about X stock', 'how is X doing', X's share price or chart, X stock analysis, valuation (P/E, forward P/E), margins, revenue, growth, debt, dividend, how far it is from its 52-week high, or 'is X expensive'. Accepts a ticker or company name. Shows a compact interactive card: price, 1-year chart, 52-week range, key fundamentals grouped as Valuation / Quality / Growth / Health, and a Buffett score strip. Covers 21,000+ stocks worldwide. Call it first, then add your own context such as recent news. For 'is X a good investment' or 'would Buffett buy X', use analyze_stock instead.