principle-subtract-before-you-add

Remove dead code, redundant validators, and stub references first, then build the feature on the simplified base. Deletion cuts the surface area and usually makes the next design obvious.

It is a sequencing rule: remove complexity before constructing anything new. Adding to a complex system compounds complexity, while subtraction reveals the essential structure and keeps the design smaller and less brittle.

Delete validators, parsers, and guards that go beyond what the specification demands. Out-of-spec features like persistence or retry-on-startup drag defensive guards behind them, so cutting the feature removes the need for its guards.

Avoid it when the code under review is actively used and covered by observed usage requirements, or when removal would break documented behavior. The principle targets dead weight and speculative edge cases, not functioning spec-required logic.

Simplify prompts by removing redundant instructions and excessive templates. When a reference document contains no novel content, delete it entirely rather than leaving a stub that adds surface without value.