{"name":"weighted_average","title":"Weighted Average Calculator","category":"math","description":"Weighted mean, sum of weights, and effective contribution of each value.","price_usd":0.001,"input_schema":{"type":"object","properties":{"values":{"type":"array","description":"Numeric values"},"weights":{"type":"array","description":"Weights, same length as values"}},"additionalProperties":false,"required":["values","weights"]}}