docs(evals): record a one-time manual comparison against upstream skill-creator

[kyle-sexton]

Refs #5255
Refs #3614

Owner decision on #5255 (2026-09-29): adopt now, once, manually.

Summary

Run one manual comparison against upstream skill-creator on claude-plugins-official and record the deltas.

• Recommendation: adopt once, manually, now. Basis: Evaluation-methodology vertical: gap analysis of fleet evals against the Agent Skills eval pipeline #3614 AC1 requires the reference implementation to be examined before any adoption decision, and gap-analysis row 9 only defers it. The one-time comparison is the AC1 deliverable; a recurring checklist is optional.
• Unblocks: AC1 of Evaluation-methodology vertical: gap analysis of fleet evals against the Agent Skills eval pipeline #3614, and every other adopt decision on evals: operator gate for the adopt proposals from the fleet-vs-Agent-Skills gap analysis (#3614) #5255.

Condition

Scope is a single manual comparison, not a recurring checklist. PR #5288's "Reference implementation: skill-creator coverage" section may already satisfy it. If so, this item closes by pointer once #5288 merges.

Related

• evals: operator gate for the adopt proposals from the fleet-vs-Agent-Skills gap analysis (#3614) #5255 (operator gate), Evaluation-methodology vertical: gap analysis of fleet evals against the Agent Skills eval pipeline #3614 (gap analysis), PR docs: remove agent-encoded decisions and correct decision records #5288

[kyle-sexton]

The issue's one deliverable, a one-time manual comparison against upstream skill-creator with the deltas recorded, is on main.

• PR docs: remove agent-encoded decisions and correct decision records #5288 merged (bb7f67e).
• docs/specs/evaluation-methodology-gap-analysis.md, "Reference implementation: skill-creator coverage" covers what skill-creator ships, what it does not, a coverage table over the pipeline rows, and a "Verdict effect" paragraph with the deltas.
• I checked the section's file inventory against the anthropics/claude-plugins-official plugins/skill-creator listing and it matches. I did not re-check its claim that nothing upstream reads evals.json.

The issue's Condition says it closes by pointer once #5288 merges, so closing as completed.