Conciseness

The ~70-line body is lean and operational throughout — commands, paths, and safety constraints with no explanations of concepts Claude already knows. Every section (Use when / Do not use when / Instructions / Commands / Installation scope / Safety) earns its tokens, matching anchor 5.

Actionability

Fully executable, copy-paste-ready npx commands cover every common case with concrete arguments ("search flutter", "install flutter-expert", "install --bundle core-dev", "doctor", "installed", "update"), plus exact destination paths and a worked AG_SKILLS_DIR example — anchor 5.

Workflow Clarity

The five-step Instructions sequence embeds explicit validation checkpoints: "Check the resolved destination with `doctor` and list existing skills before replacing them", "Do not report success after a nonzero exit status", and "Report the command's actual installed, updated, skipped, and failed counts". Error-recovery guidance (preserve backups, follow the reported recovery path) is also present, so the destructive/batch-operation cap does not apply — anchor 5.

Progressive Disclosure

This is a self-contained, single-purpose skill with no bundle files; content is appropriately inline, sections are well-organized, and the only external pointers (official skill-locations and plugin docs) are clearly signaled one-level links — matching the simple-skill standard for anchor 5.

Specificity

"Searches, installs, updates, and lists skills from the Antigravity Skill Vault" names the domain and four concrete operations, but the inspect/doctor capability and what the skills are for remain implicit — minor gaps in coverage matching anchor 4 rather than the comprehensive anchor 5.

Completeness

Both a clear "what" (four concrete operations on the Skill Vault) and an explicit "when" ("Use when choosing or managing workspace or global skills through the npm CLI") are present, but the trigger phrase is less concrete than anchor 5's exemplar of user-mentionable trigger phrases.

Trigger Term Quality

"skills", "install", "update", "workspace or global", and "npm CLI" give good natural keyword coverage a user would plausibly say, but common synonyms like "add skill" or "skill manager" are missing, fitting anchor 4 rather than the fully comprehensive anchor 5.

Distinctiveness Conflict Risk

"Antigravity Skill Vault" and the npm CLI scope establish a clear niche distinct from generic file or document skills, with only minor overlap risk against other generic skill-manager skills — anchor 4 rather than the minimal-conflict anchor 5.