Conciseness

The body is lean — tables for config fields, database selection, and troubleshooting, with no explanation of concepts Claude already knows — but a few Safety Features bullets describe internal implementation details Claude cannot act on ("Column width cap: 100 char max per column", "Memory protection: Max 10,000 rows"), which is minor over-explanation that could be trimmed. This fits anchor 4 (efficient with minor trimmable instances), not 5 (every token actionable) and clearly not 3 (no padded or unnecessary conceptual sections).

Actionability

Guidance is essentially copy-paste ready: complete executable commands for every operation ("python3 scripts/query.py --db production --query \"SELECT * FROM users LIMIT 10\""), a full connections.json example, and CLI flags that match the actual script. The gap is that Setup says "pip install -r requirements.txt" but requirements.txt does not exist in the bundle, so that command fails as shipped — a minor gap matching anchor 4 rather than 5, and well above anchor 3 (all real commands are executable, not pseudocode).

Workflow Clarity

The Workflow section gives a clear four-step sequence (list → match intent → explore structure → query with LIMIT) with a decision checkpoint ("If unclear, run --list and ask user") and the Troubleshooting table supplies error-to-fix recovery paths. Validation is implicit rather than an explicit step (e.g., verifying a table via --tables before querying), which keeps it at anchor 4; it is above anchor 3 because the sequence and checkpoints are mostly present, and the destructive/batch cap does not apply since the skill is strictly read-only with write-blocking enforced.

Progressive Disclosure

Structure is appropriate: SKILL.md is a well-organized overview (setup, usage, selection, safety, troubleshooting, exit codes) and the only bundle file, scripts/query.py, is correctly referenced and verified. Nothing that belongs in a separate file is inlined, references are one level deep, and navigation is trivial — matching anchor 5. Not 4, since there are no organization gaps or misplaced content.

Specificity

Concrete actions are named — "Execute read-only SQL queries against multiple PostgreSQL databases", "Blocks all write operations (INSERT, UPDATE, DELETE, DROP, etc.)" — but the capability surface (listing tables, showing schema, limiting results) is implied via trigger clauses rather than stated as actions, leaving minor gaps in coverage. Not 3 (multiple concrete actions are explicit) and not 5 (thinner action list than the comprehensive anchor example).

Completeness

Explicitly answers both questions: the what ("Execute read-only SQL queries against multiple PostgreSQL databases") and the when ("Use when: (1) querying... (2) exploring... (3) running SELECT queries... (4) checking database contents") with concrete numbered trigger phrases. This matches the anchor-5 example structure exactly; it is clearly above anchor 4 since the when-clause is fully explicit and enumerated.

Trigger Term Quality

Natural phrases users would say are present: "querying PostgreSQL databases", "exploring database schemas/tables", "running SELECT queries", "checking database contents". Common variants like "Postgres" (without the -QL suffix) and generic "SQL" are missing, so coverage is good but not comprehensive — matches anchor 4, not 3 (many natural terms present) or 5 (synonyms/extensions not exhaustive).

Distinctiveness Conflict Risk

A clear niche is staked out — read-only PostgreSQL querying with write-blocking — and every trigger is database/PostgreSQL-specific, so it is unlikely to fire for unrelated skills. The domain is narrower than the anchor-4 example ("PDF and Word documents"), matching anchor 5's minimal-conflict profile.