The body is lean and assumes Claude's competence — a table of impact areas, terse safety rules, and bullet-listed traps with no padding or explanation of concepts Claude already knows. Every line carries actionable signal.

Provides concrete executable guidance: exact paths (veomni/data/data_collator.py), commands (pytest tests/), grep instructions ('grep all YAML files first'), and specific ordering constraints ('pad → slice → FA kwargs → slice position_ids') that are copy-paste ready.

The Refactoring Safety Rules section gives a clear numbered sequence with explicit validation checkpoints ('run pytest before any change, record results', 'verify tests match baseline', 'Check baseline again at the end — results must be identical'), including a feedback loop of baseline comparison.

No bundle files exist (references/scripts/assets absent), and the body is well-organized into clearly headed one-level sections (Impact Analysis, Refactoring Safety Rules, Common Traps, Documentation, routing) with no nested references — appropriate for a self-contained checklist skill.

Names the domain and several affected areas ('modalities, trainer hierarchy, data pipeline, and distributed code') but lists areas of analysis rather than multiple concrete actions the skill performs, so it falls short of the 'lists multiple specific concrete actions' anchor.

Clearly answers what it does ('checklist for feature development and refactoring' covering specific areas) and when to use it with an explicit 'Use before implementing any non-trivial change' and a 'Trigger:' clause, satisfying both what AND when.

Includes natural user phrasing in the explicit Trigger clause ('add feature', 'implement', 'refactor', 'reorganize', 'new capability') that users would plausibly say, giving good coverage of natural terms.

Defines a clear niche (VeOmni feature development/refactoring) and explicitly routes overlapping cases away ('use veomni-new-model or veomni-new-op instead'), making it unlikely to trigger for the wrong skill.