Conciseness

The body is lean and assumes Claude's competence: no concept explanations, no tool tutorials, just directives like "Use `xcodebuild test` for Xcode-based projects" and "Distinguish compilation failures from test execution failures". Every section earns its tokens, matching the top anchor rather than the 4 anchor ("minor instances of over-explanation").

Actionability

Concrete commands are named (`xcodebuild test`, `swift test`) and the six-category failure taxonomy plus output checklist are specific, but the rerun and scope-narrowing steps lack executable specifics (no example flags like `-only-testing:` or `--filter`, no example commands). This sits between the 3 anchor (missing key details) and the 5 anchor (copy-paste ready commands) but noticeably above the midpoint.

Workflow Clarity

A clear five-step sequence (detect harness → narrow scope → classify → rerun → summarize) with a built-in decision loop ("Use focused reruns when a specific case fails... without new information") and an output checklist. It misses a 5 because there is no explicit verify-the-fix checkpoint; it exceeds 3 because the sequence and checkpoints are explicit rather than implicit, and no destructive/batch validation cap applies.

Progressive Disclosure

The skill is under 50 lines, needs no external references (none exist in the bundle), and is organized into four clearly labeled sections (Quick Start, Workflow, Guardrails, Output Expectations) with nothing inlined that belongs in a separate file — matching the simple-skill exception for a top score.

Specificity

The description lists several specific actions — "Triage failing macOS tests across Xcode and SwiftPM workflows", "run macOS tests, narrow failing scopes, explain assertion or crash failures, or separate real test regressions from setup and environment problems" — with only minor coverage gaps (e.g., rerun strategy, log parsing). It falls below 5, which demands comprehensive multi-action coverage, and above 3, which expects only 1-2 concrete actions.

Completeness

It explicitly answers what ("Triage failing macOS tests across Xcode and SwiftPM workflows") and when ("Use when asked to run macOS tests, narrow failing scopes, explain assertion or crash failures, or separate real test regressions from setup and environment problems") with multiple concrete trigger phrases, matching the top anchor exactly.

Trigger Term Quality

Natural phrases users would say are present: "run macOS tests", "narrow failing scopes", "explain assertion or crash failures", "Xcode", "SwiftPM", "test regressions", "setup and environment problems". A few common variations are missing ("flaky tests", "unit tests", "CI failures"), placing it between the 3 and 5 anchors but noticeably above the midpoint.

Distinctiveness Conflict Risk

The niche is clearly delimited — macOS test triage across two named toolchains (Xcode and SwiftPM) — and the trigger phrases are specific to test-failure diagnosis, giving minimal conflict risk with other skills. It fits the 5 anchor better than the 4 anchor, which presumes overlap with closely related skills.