Conciseness

The body is lean and imperative with zero basic-concept padding ("A gate that did not print green is not green", "Look at the bytes"), but the two opening paragraphs state the same look-at-real-output motivation twice, which is a minor trimmable instance of over-explanation. Anchor 4 fits better than 5, which demands every token earn its place.

Actionability

Every step is copy-paste executable with concrete flags and values: `./dev.sh --dry-run`, the full `dotnet run ... --seed 42 --output-path "$OUT"` invocation, `unzip -l`/`unzip -p`/`xxd` inspection, `dotnet publish` plus `ZIPPER_CLI=... run-goldens.sh`, and a named `--capture --scenario pdf-metadata` example. This matches anchor 5 (fully executable, common cases covered).

Workflow Clarity

Five clearly sequenced sections with explicit validation checkpoints ("Hashes must match", "Then open what it produced"), an explicit feedback loop ("Fix the root cause, rerun the same gate"), a defined failure-reporting protocol, and a red-flags checklist. This matches anchor 5; the destructive/batch cap does not apply because validation and parity checks are thoroughly specified.

Progressive Disclosure

Sections are well-organized and the skill is appropriately self-contained with no nested references, but at roughly 93 body lines it exceeds the under-50-line simple-skill threshold, and "Critical Rule 6" and "Critical Rule 4 (README, Requirements, glossary, E2E scripts)" are invoked without paths or links to where they live. Anchor 4 (good structure, minor organization gaps) fits better than 5.

Specificity

The only stated action is "to gather real-artifact evidence before the claim"; the domain is well-named ("CLI behavior, Load File formats, Production Sets, or output bytes") but the description never lists concrete verification actions like running gates, inspecting output bytes, or comparing golden manifests. This matches anchor 3 (names domain and 1-2 concrete actions) rather than 4, which requires several specific actions.

Completeness

The 'when' is explicit and strong ("Use when about to claim a Zipper change is done, fixed, or passing"), and a 'what' is present ("to gather real-artifact evidence"), but the 'what' is generic rather than concrete. Anchor 4 fits (both present, one could be more specific); anchor 5 requires both to be clearly and concretely stated.

Trigger Term Quality

"done, fixed, or passing" are natural trigger phrases paired with concrete contexts ("claim a Zipper change", "CLI behavior", "output bytes"), giving good keyword coverage. A few natural terms are missing (e.g., "verified", "green", "tests pass"), so it falls just under anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

The description is scoped to "a Zipper change" with project-specific artifacts ("Load File formats, Production Sets"), creating a clear niche with distinct triggers and minimal conflict risk with other skills, matching anchor 5.