What problem does it solve? Claude Code skills often fail silently: descriptions that never trigger, frontmatter that drifts from the schema, broken references to bundled scripts, or missing side-effect guards. This Skill reviews PR diffs touching skill files and catches those authoring defects before merge. ## Core Features & Use Cases - Frontmatter and description validation: Enforces schema rules for name, description length, trigger phrasing, voice, and allowed-tools syntax against canonical Anthropic references. - Structural and safety checks: Verifies referenced files exist, scripts use ${CLAUDE_SKILL_DIR}, side-effecting skills set disable-model-invocation: true, and renames update all cross-references. - Severity-calibrated findings: Emits JSONL findings tagged with rule codes (e.g. R-DESCRIPTION-TRIGGERS), source docs, and P0–P3 severity so authors can verify each claim. - Use Case: A PR adds a new skill under plugins/foo/skills/bar/SKILL.md. Run this lens to catch that its description starts with "Use this skill when…", its body is second-person, and its scripts/run.sh is never referenced. ## Quick Start Review the skill file changes in this PR for authoring issues and report findings with rule codes and severity.