Verifying documentation parity

This skill is the judgment that code has drifted away from the documentation which describes it. It enforces the base obligations of the documentation standard: docs and diagrams update in the same change as the code they describe, and a change that invalidates documentation the repo does not contain gets called out at review.

Contexts

The skill runs in two contexts where change source and relevant document discovery differ.

• Agent session, invoked by the doc-parity Stop hook or on demand. The change is the working tree (git diff HEAD plus untracked files). Verification is in-repo only.
• Pull request review, run through the ai-review workflow. The change is the PR diff plus the PR description. In addition to in-repo verification, this context performs out-of-repo discovery. A review never edits: where a session would apply an Update, the review calls out the in-repo doc that needs the change and what it must say.

Workflow

Step 1: Assemble the change

Collect the full set of changed files and read the diff, not just the file list, because judging drift requires knowing what the change does. In a session, use git diff HEAD and git ls-files --others --exclude-standard. In a review, use the PR diff and read the PR description for intent.

Before walking the tree, consider whether the change qualifies as a tripwire false positive: a formatting-only diff, generated output, or a doc-comment-only edit that the Stop hook classified as code. When it does, dismiss the check with a one-line reason naming the false-positive class and end the skill.