Nine excellent constraints and one missing idempotency clause still double-charges customers under retry. Constraints are not additive polish; each one closes a specific failure mode, and the ones you omit stay open in production regardless of how good the rest of the prompt is.
Each law names a structural truth about AI-assisted development — independent of model choice, stable across versions. The full treatment, with working examples in C#, Java, Python, and TypeScript, is in the book. Free, no email gate.