Conciseness

Nearly all content is non-obvious, project-specific operational detail rather than concepts Claude already knows, but the body runs ~1170 lines with clear duplication that could be tightened: the first-party native package prohibition is restated roughly six times (Core Principles, D2 gate, D3 routing, D3.1 precheck, D3.2 constraints, Constraints), and the host-diagnostic string catalog appears in both the Dev-client limitation note and Step A's interpretation rule. This is more than minor trimming (not 4) yet the verbosity is contextual restatement of dense actionable material rather than padded explanation (not 2).

Actionability

Fully executable throughout — copy-paste-ready bash and inline Node scripts (the cursored tail reader, liveness probes, the redaction verifier invocation), exact JSON state schemas (metro-cursor.json, health.json), concrete pattern→action routing tables (Step B, D3, D3.1), an exact console.log injection format with a cleanup grep key, and literal output templates for every exit path.

Workflow Clarity

The multi-phase workflow (Phase 0 preflight/discovery/baseline → Phase 0.5 symptom walk → monitor loop Steps A–D) is clearly sequenced with explicit validation checkpoints and feedback loops: type-check gate before advancing, re-poll fix verification, the supersession check before editing code, escalation after 2 failed attempts, the 50-cycle iteration cap, and verified cleanup of injected traces before any exit.

Progressive Disclosure

The single bundle reference (references/startup-diagnostics.md) is real, clearly signaled, and linked at exactly the right dispatch points, but the SKILL.md itself inlines hundreds of lines that belong in separate reference files — the D3.1 bundle-recipe catalog, the D3.2 best-effort procedure, the host-diagnostic string lists, the Failure Modes table, and the upstream parity table. Structure and signaling are better than the 2-anchor's 'minimal structure', but the volume of inlined detail that should be split out exceeds the 4-anchor's 'minor organization gaps'.

Specificity

The description lists multiple specific concrete actions with comprehensive domain coverage — "Diagnose Power Apps mobile install/startup failures, npm run dev errors, missing package entry points, or QR/device-opening problems", "monitor sanitized project-local Metro logs and diagnose runtime errors or silent failures such as empty lists and blank screens", and "Verify the original symptom, not merely installation or quiet logs" — all in third person.

Completeness

Clearly answers "what" (diagnose startup failures, monitor Metro logs, diagnose runtime errors and silent failures) and provides explicit conditional trigger guidance ("even before an app is loaded", "For a running native app"), but there is no direct "Use when…" clause and the when-guidance could be more explicit. This matches the anchor where both are present but 'when' could be more specific rather than the 3-anchor (what-only) or 5-anchor (concrete 'Use when' trigger phrases).

Trigger Term Quality

Good keyword coverage with natural user phrasings ("npm run dev errors", "QR/device-opening problems", "empty lists and blank screens", "silent failures", "startup failures"), but common variations users would say are missing (e.g., "app won't start", "crash", "fix", "debug"). Not score 3 because the included terms are natural and varied; not 5 because synonym coverage is incomplete.

Distinctiveness Conflict Risk

A clear niche with distinct triggers — "Power Apps mobile", "project-local Metro logs", "MSAL", "port/platform filters" — that no generic debugging skill would share; minimal conflict risk.