Conciseness

The body is almost entirely tables and executable SQL with terse one-line comments ("Wrap in SELECT!", "O(1) vs OFFSET which is O(n)") and zero padding or explanation of concepts Claude already knows. A minor blemish is the malformed heading "反模式检测\*\*", but it does not add unnecessary tokens, so this does not drop it from the lean-and-efficient anchor.

Actionability

Fully executable copy-paste SQL covering the common cases: index DDL, RLS policy, UPSERT with ON CONFLICT, cursor pagination, a FOR UPDATE SKIP LOCKED queue query, and diagnostic queries against pg_stat_statements. Not 4 because the examples are concrete and complete rather than having minor gaps; the generic t (col) placeholders in the cheat table are a reasonable reference-table idiom.

Workflow Clarity

As a reference skill it has a clear '何时激活' section and delegates the full workflow to the database-reviewer agent, but there are no multi-step sequences with validation checkpoints. The 配置模板 section applies risky system-wide changes (ALTER SYSTEM SET max_connections = 100, REVOKE ALL ON SCHEMA public FROM public) with no verification or rollback guidance, and the rubric caps this dimension at 3 for database operations missing feedback loops.

Progressive Disclosure

Well-organized single-file quick reference (~150 lines) with clear sections and a '相关' pointer to sibling skills, but no reference files exist at all, and the anti-pattern queries and config templates are content that could live in references/. Anchor 4 (good structure, minor organization gaps) rather than 5 because the under-50-line simple-skill exception does not apply and the file is larger than a pure overview.

Specificity

Names the domain ("PostgreSQL") plus four concrete capability areas — "查询优化" (query optimization), "模式设计" (schema design), "索引" (indexing), "安全性" (security) — matching the anchor for several specific actions with minor gaps. Not 5 because these are topic areas rather than multiple concrete actions, and "基于Supabase最佳实践" is provenance, not a capability; not 3 because four areas exceed the 1-2 actions of that anchor.

Completeness

The 'what' is clear (PostgreSQL patterns for query optimization, schema design, indexing, security), but the 'when' is entirely absent with no equivalent trigger guidance, which caps completeness at 3 per the judging guidelines. Not 4 because nothing even weakly implies when to activate the skill.

Trigger Term Quality

Contains some relevant keywords ("PostgreSQL", "查询优化", "索引", "模式设计") but no 'use when' phrasing and no natural user phrases or synonyms such as "slow query", "migration", "RLS", "连接池", matching the anchor for some relevant keywords with missing variations. Not 4 because the common natural terms a user would actually say are largely absent.

Distinctiveness Conflict Risk

A clearly PostgreSQL-specific niche ("PostgreSQL数据库模式") with only minor overlap risk against closely related skills like the referenced clickhouse-io or database-reviewer. Not 5 because generic terms like "安全性" (security) could brush adjacent skills, and with no trigger clause there is little to disambiguate.