skills / Engineering Principles
principle-build-the-lever
Build the smallest rerunnable tool that performs or proves non-trivial work. Use for migrations, repetitive edits, analyses, audits, generators, or delegated campaigns where hand work would drift or be hard to review.
Build the lever
When work is non-trivial, make the method a rerunnable artifact: a codemod, script, query, generator, checker, or delegate contract. The lever buys both throughput and reviewability.
Pattern
- Perform one representative unit by hand to learn the recipe.
- Build the smallest deterministic tool that reproduces or verifies that unit.
- Diff the tool's result against the hand-worked unit.
- Make reruns safe: idempotent where possible, scoped, and loud on partial failure.
- Run it across the remaining units and retain its proof output.
Prefer a deterministic script to agents hand-applying the same transformation. When the work genuinely requires judgment and delegation is authorized, make the lever a read-only contract every worker follows: goal, recipe, verification predicate, output schema, and do-not-touch fences. Keep that contract outside worker write scopes.
Applying this principle produces a file. If no script, generator, query, checker, or delegate contract exists, the lever was not built. Skip only a couple of obvious edits whose result is cheaper to inspect than the tool would be to maintain.
Commit the lever when the task or its verification will recur; otherwise keep it as a visible run artifact.