Trimming Chain-of-Thought Leakage

Chain-of-thought leakage is prose whose vantage is the authoring session rather than the repository: it cites artifacts only that session could see, narrates the change instead of the state, or argues with a reviewer who has left. The fix is never deletion alone when a passage carries factual clauses — restate each so it stands on its own, then delete the transcript around it; a passage carrying none is deleted outright. Before editing, enumerate the complete proposition: preserve each actor, action, condition, timing, modality, negative guarantee, exception, ownership, side effect, failure mode, and consequence. It is guidance, not a script.

The one test

For every suspect passage ask: could a reader with no access to any session transcript, PR thread, or uncommitted draft resolve every reference and verify every claim? If no, restate the surviving facts and delete the rest. If yes, it is not leakage — but a resolvable change story on a current-state surface (README, docs, skill body) is still change narration and belongs in a commit, PR, or Agent Note.

Taxonomy

1. Dead design-session citations — (decision 7), (audit C2), design §4.7, phase labels (T4, W3). If the decision has a committed owner, cite it by name and path; otherwise delete the citation and restate its factual clause.
2. Stack and PR vantage — "a later PR in this stack", "this PR adds", "the previous commit". State the shipped mechanism; deferred work becomes a TODO marker or an issue reference.
3. Change narration and version stamps — "used to", "no longer", "the old X", and indexical stamps ("v1", "this cut", "today"). State the present behavior; a fixed regression becomes a present-tense counterfactual ("without X, Y happens"), never repo history.
4. Review choreography — "rejected in review", "the reviewer confirmed", draft ordinals ("v5 of this note"). Keep the surviving decision and rationale as plain fact.
5. Reviewer-addressed justification — "the cast is safe — it simply…", "this is correct because…". State the invariant that makes the code or rule safe, or delete the comment.
6. Restatement and derivation transcripts — control-flow narration ("first we X, then we Y"), proofs of obvious branches. Delete; keep only a non-obvious contract.
7. Hedges and planning residue — "probably fine for now", "should be enough", deferrals with no marker. Promote to TODO/FIXME or restate as the actual bound.
8. Authoring-language slips — untranslated fragments in prose whose language is otherwise English, or the reverse in a .zh.md counterpart. Translate or delete.