Clean-code law

The budget

Every source file is budgeted at 250 words (hard cap 350, enforced by a pre-write hook and CI — not a review comment). Bloat physically cannot land. Big features become small, navigable modules; DRY is checked against the knowledge graph, not memory.

The framework holds itself to the same cap — every .py in Atelier passes its own audit.

The ponytail reflex

Before every line, the agent interrogates itself on a descending ladder and stops at the first rung that holds:

1. Does this need to exist at all? (YAGNI)
2. Already in this codebase? Reuse it.
3. Standard library does it? Use it.
4. Can it be one line? One line.
5. Only then — the minimum that works.

Deliberate shortcuts are marked with a ponytail: comment naming the ceiling and the upgrade path, so deferred work is tracked instead of forgotten.

Comment policy

Comments state constraints the code can’t show — never what the next line does or why a change is correct. Root-cause fixes over symptom patches: one guard in the shared function beats a guard in every caller.

Full text: skills/clean-code-law/SKILL.md