{"name":"compound_interest","title":"Compound Interest / Future Value Calculator","category":"finance","description":"Future value, total contributions and interest with optional periodic deposits.","price_usd":0.002,"input_schema":{"type":"object","properties":{"principal":{"type":"number","description":"Starting principal in USD"},"annual_rate_pct":{"type":"number","description":"Annual interest rate as a PERCENT (6 = 6%)"},"years":{"type":"number","description":"Number of years"},"compounds_per_year":{"type":"integer","description":"Compounding periods per year (default 12)"},"contribution":{"type":"number","description":"Deposit added each compounding period, USD"}},"additionalProperties":false,"required":["annual_rate_pct","years"]}}