Conciseness

Prose is lean and assumes Claude's competence, but the body carries substantial trimmable bulk: ~50 diagnostics table rows that the skill itself admits are incomplete ("ships more files than are listed here") and discoverable via the included `ls` command, plus a routing decision tree that repeats guide filenames already tabulated above. That is more than anchor 4's 'minor instances', fitting anchor 3's 'could be tightened'.

Actionability

Guidance is fully executable: exact base directories, a copy-paste example ("Read /Applications/Xcode.app/.../SwiftUI-Implementing-Liquid-Glass-Design.md"), a concrete `ls` command, explicit filename-to-topic tables, and a deterministic path-resolution procedure (session context → AXIOM_XCODE_PATH → `xcode-select -p` → default). Specific examples cover the common cases, matching anchor 5.

Workflow Clarity

The path-resolution sequence is clearly ordered with explicit conditional checkpoints ("If it prints /Library/Developer/CommandLineTools, no Xcode is selected") and an error-recovery fallback chain ending in "Do not silently fail — tell the user", matching anchor 4. It falls short of anchor 5 only because there is no explicit check that a specific guide/diagnostic file exists before reading it — the ls fallback appears only in the diagnostics section's tail and the tree's 'Other' branch.

Progressive Disclosure

The bundle contains no references/, scripts/, or assets/, and the body's only cross-references point to "skills/apple-docs-research.md", which does not exist in the bundle — a dangling reference. Meanwhile ~50 rows of diagnostics catalog are inlined in SKILL.md where the rubric expects an overview pointing to a separate index file, fitting anchor 3 ('content that should be separate is inline; references present but not clearly signaled') rather than anchor 4's 'most content appropriately placed'.

Specificity

The description names its domain ("Apple's own documentation or a Swift compiler diagnostic") but offers only one generic action verb — "explained" — matching the anchor 'Names the domain but actions are minimal or generic' (cf. "Processes PDF files"). The qualifier "rather than recalled" sharpens intent without adding a concrete capability, so it does not reach anchor 3's '1-2 concrete actions'.

Completeness

The explicit "Use when..." clause satisfies the trigger requirement, and the 'what' — needing Apple's documentation or a diagnostic "explained rather than recalled" — is stated within the same sentence, so both are present. It is not anchor 5 because the 'what' is not stated as a standalone capability with concrete trigger phrases, and not anchor 3 because the 'when' is explicit rather than weakly implied.

Trigger Term Quality

"Apple's own documentation" and "Swift compiler diagnostic" are relevant keywords, but common natural phrasings are missing: users say "compiler error" or "warning" far more than "diagnostic", and "Xcode docs", "Apple docs", or "API reference" are absent. This fits anchor 3 ('some relevant keywords but missing common variations or synonyms') rather than anchor 4's good coverage.

Distinctiveness Conflict Risk

"Apple's own documentation" and "Swift compiler diagnostic explained rather than recalled" carve a clear niche with distinct triggers, and the "rather than recalled" qualifier separates it from generic Apple/Swift Q&A skills. Minor overlap risk remains with sibling skills like the referenced apple-docs-research skill, keeping it below anchor 5's minimal conflict risk.