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mvcc-isolation-tests

Use when two concurrent database transactions can touch the same rows (balance debits, seat bookings, stock counts), or before changing a default isolation level. Tests which anomalies each level prevents (dirty, non-repeatable and phantom reads, write skew) in PostgreSQL, MySQL and SQL Server.

Quality

95%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

The canonical home for this skill is testland/mvcc-isolation-tests

SKILL.md
Quality
Evals
Security

Quality

Content

92%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

Excellent content: fully executable code with a validation checkpoint step and per-test state checks, and a clean one-level reference split for per-database differences. Only minor conciseness trims are available (known-concept anomaly definitions and environment version notes).

DimensionReasoningScore

Conciseness

The body is dense and assumes competence, but the anomaly-shape table re-defines concepts Claude already knows (e.g. 'T2 reads T1's uncommitted write') and the version-specific 'ran 5/5 green on PostgreSQL 16 with psycopg 3' is trimmable detail outside any deprecated/old-patterns section.

4 / 5

Actionability

The skill ships a complete, copy-paste-ready pytest harness (fixture, run_pair, four anomaly tests, retry wrapper) plus an exact run command with TEST_DSN and a table mapping business invariants to test shapes.

5 / 5

Workflow Clarity

Steps 1-4 are clearly sequenced and Step 4 is an explicit validation checklist ('must fail when you raise the isolation level by one step. Try it.'), while the harness itself validates starting state per test, asserts recorded errors, and detects hangs - feedback loops are present in this database context.

5 / 5

Progressive Disclosure

Content is appropriately split: the PostgreSQL matrix and harness stay inline while MySQL/SQL Server differences live in the real, well-signaled, one-level-deep references/per-database.md, linked in three places and listed under References.

5 / 5

Total

19

/

20

Passed

Description

95%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: explicit 'what' and 'when' in third person, natural trigger phrases including concrete business scenarios, and a distinctive niche. The only minor gap is that capability coverage hinges on one enumerated action rather than several distinct ones.

DimensionReasoningScore

Specificity

The action 'Tests which anomalies each level prevents' is concrete and enumerated across dirty, non-repeatable and phantom reads, write skew, in PostgreSQL, MySQL and SQL Server, but coverage rests on a single action verb rather than multiple distinct actions.

4 / 5

Completeness

Explicit 'Use when two concurrent database transactions can touch the same rows... or before changing a default isolation level' answers 'when' with concrete triggers, and 'Tests which anomalies each level prevents...' clearly answers 'what' in third person.

5 / 5

Trigger Term Quality

Natural user phrasing is comprehensively covered: 'concurrent database transactions', 'balance debits, seat bookings, stock counts', 'isolation level', 'write skew', plus all three engine names, giving strong synonym and scenario coverage.

5 / 5

Distinctiveness Conflict Risk

The concurrency-on-same-rows and isolation-level-change triggers carve out a clear niche with named engines, so overlap with generic database-testing skills is minimal.

5 / 5

Total

19

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

testland/qa

Path

plugins/qa-concurrency/skills/mvcc-isolation-tests/SKILL.md

Reviewed

Table of Contents

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