{"name":"normal_prob","title":"Normal Distribution Probability","category":"statistics","description":"CDF, survival, z-score, and percentile queries for any normal distribution.","price_usd":0.001,"input_schema":{"type":"object","properties":{"mean":{"type":"number","description":"Distribution mean (default 0)"},"std_dev":{"type":"number","description":"Standard deviation > 0 (default 1)"},"x":{"type":"number","description":"Point for P(X<=x), P(X>x), z-score"},"a":{"type":"number","description":"Lower bound for P(a<X<b)"},"b":{"type":"number","description":"Upper bound for P(a<X<b)"},"percentile":{"type":"number","description":"0..100 -> value at that percentile"}},"additionalProperties":false}}