version: "1.0.1" name: principle-subtract-before-you-add description: "Apply when sequencing an addition, refactor, or rewrite. Remove dead weight, redundant validators, and stub references first, then build on the simpler base." disable-model-invocation: true

Subtract Before You Add

When evolving a system, remove complexity first, then build. Deletion gives you a simpler base, which makes the next addition smaller and less brittle.

Why: Adding to a complex system compounds complexity. Removing first cuts the surface area, reveals the essential structure, and usually makes the next design obvious. Default to subtraction.

Make simplification a continual investment. Leave the design slightly simpler and more capable behind the same or smaller surface than you found it.

The pattern:

• Sequence removal before construction
• Cut before you polish (get to the minimum before investing in quality)
• Design for observed usage, not speculative edge cases
• No speculative validators, parsers, or guards beyond what the spec demands
• Out-of-spec features drag validators behind them. Persistence, retry-on-startup, and schema migration each need guards to defend their inputs.
• Simplify prompts (remove redundant instructions, excessive templates)
• When a reference has no novel content, delete it rather than leaving a stub