Conciseness

The 8-line body contains zero padding or explanation of things Claude already knows; every line either instructs or gives the exact output. It matches the 'lean and efficient; every token earns its place' anchor.

Actionability

"Reply with exactly one line" followed by the literal output "ACR-CANARY-SKILL-7f3a discovered" is copy-paste-ready and fully unambiguous, matching the 'fully executable' top anchor. As an instruction-only skill, the concrete, specific guidance fully satisfies the rubric without code.

Workflow Clarity

This is a simple single-purpose skill with one unambiguous action and an explicit termination instruction ("Do nothing else. Finish here."), so the rubric's simple-skill exception applies and workflow clarity scores 5. There are no destructive or batch operations, so no validation cap applies.

Progressive Disclosure

The skill is under 50 lines, well-organized with a clear heading, and needs no external references (verified: no references/, scripts/, or assets/ bundle files exist), matching the rubric's simple-skill exception for progressive disclosure.

Specificity

The description names the domain ("ACR canary skill") and one concrete action ("Report that the ACR canary skill was discovered"), matching the '1-2 concrete actions, but not comprehensive' anchor. It does not list several actions, so it falls below anchor 4, and its single action is concrete rather than generic, keeping it above anchor 2.

Completeness

It explicitly answers both 'what' ("Report that the ACR canary skill was discovered") and 'when' ("Use when asked to run the ACR canary, list available skills, or confirm skill discovery") with three concrete trigger phrases, matching the top anchor exactly. The 'when' clause is explicit and specific, so it exceeds anchor 4.

Trigger Term Quality

It includes multiple natural phrases users would say — "run the ACR canary", "list available skills", "confirm skill discovery" — giving good keyword coverage. A few natural variants (e.g. 'check the canary', 'skill check') are missing, so it does not reach the comprehensive-synonym coverage of anchor 5.

Distinctiveness Conflict Risk

The ACR canary is a distinct niche with dedicated triggers, but the broad phrase "list available skills" carries minor overlap risk with general skill-listing or meta skills, matching 'mostly distinct; minor overlap risk' rather than the minimal-conflict anchor 5.