Conciseness

The symptom→file routing map is repeated four times in different formats (Quick Reference table, dot-graph decision tree, numbered decision list, and Example Invocations), and the 'Critical Patterns' section further summarizes the contents of the referenced files. This is genuinely useful routing content, but the duplication is more than the 'minor instances of over-explanation' the 4-anchor allows and could be tightened to one or two formats.

Actionability

Routing guidance is concrete and executable — exact file paths per symptom ("Read: skills/swift-concurrency.md"), exact crash signatures (_dispatch_assert_queue_fail, _swift_task_checkIsolatedSwift), explicit MCP tool mappings (xclog launch → axiom_xclog_launch), and a failure path ('If a required MCP tool is unavailable, stop and report'). It falls short of fully copy-paste-ready guidance, and the routing targets themselves do not resolve within the provided bundle.

Workflow Clarity

The decision process is clearly sequenced (decision tree plus numbered decision list covering symptom classes, with cross-skill conflict-resolution ordering like 'Try concurrency FIRST' before axiom-performance) and includes an explicit failure checkpoint for the MCP boundary. No validation steps are required for non-destructive routing, so the anchor-5 feedback loops are not applicable, but a couple of decision-tree branches overlap ambiguously.

Progressive Disclosure

The routing structure itself is well-signaled and one level deep (table + decision tree + per-file summaries), but every referenced path — skills/swift-concurrency.md, skills/swift-concurrency-ref.md, skills/synchronization.md, skills/assume-isolated.md, skills/isolation-inheritance-diag.md, skills/concurrency-profiling.md, plus cross-skill references — is absent from the bundle (no references/, scripts/, assets/, or skills/ directories exist), so the disclosure chain is broken and unverifiable as shipped.

Specificity

The description lists several concrete items — "Covers Swift 6 concurrency, @MainActor, Sendable, data races, async/await patterns" — but 'Covers' is a scope verb enumerating topics rather than concrete capability actions (cf. the 5-anchor's 'Extract text... fill forms... merge documents'), leaving minor gaps in what the skill actually does with those topics.

Completeness

Both halves are explicitly present: an explicit trigger clause ("Use when writing ANY async code, actors, or threads in an Apple-platform app, or seeing ANY concurrency error") with concrete trigger phrases, and a clear 'what' ("Covers Swift 6 concurrency, @MainActor, Sendable, data races, async/await patterns"). The 4-anchor ('when' could be more explicit) does not fit because the 'when' is already maximally explicit.

Trigger Term Quality

Good natural-keyword coverage — "async code", "actors", "threads", "data races", "async/await", "Swift 6", "concurrency error" are phrases users would naturally say — but common variations like "threading", "main thread", "Task", or "TaskGroup" are missing, so it falls just short of the comprehensive-synonyms anchor.

Distinctiveness Conflict Risk

The description carves a clear niche via platform- and language-specific terms — "Apple-platform app", "Swift 6 concurrency", "@MainActor", "Sendable" — that no generic or neighboring skill would share, giving minimal conflict risk.