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testland/testcontainers

Brings up real backing services (databases, message brokers, browsers, anything dockerizable) as throwaway containers from inside a test process - Java, Node.js, Python, Go, .NET, Ruby and ten other languages - using the Testcontainers library family. Wires the per-test container lifecycle, exposed-port → host-port mapping, wait strategies (port / log / HTTP / SQL), Ryuk-based cleanup, container-to-container networks, and the (experimental) `withReuse` shortcut for local dev. Use when integration tests need a real Postgres / Redis / Kafka / Selenium / etc. and the team wants per-test isolation without hand-rolled docker-compose teardown.

75

Quality

94%

Does it follow best practices?

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SecuritybySnyk

High

Do not use without reviewing

Overview
Quality
Evals
Security
Files

Quality

Content

85%

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

The body is highly actionable with executable multi-language examples and a clear step sequence, well-organized for navigation. Its main weakness is conciseness: an overview definition quote, a repeated language list, and a redundant References summary could be trimmed.

Suggestions

Remove the quoted definition of what Testcontainers is in the Overview and the repeated 11-language list - the description already conveys both - keeping only the lifecycle/Ryuk specifics that are non-obvious.

Tighten the References section to bare link pointers instead of re-summarizing what each link covers; the surrounding sections already state the relevant facts.

Trim explanatory prose around code blocks (e.g. the withTimes(2) rationale) to one line so each token more clearly earns its place.

DimensionReasoningScore

Conciseness

Mostly efficient with concrete code, tables, anti-patterns and limitations earning their tokens, but it includes some tighten-able prose - e.g. the Overview quotes a full definition of what Testcontainers is ('a library that provides easy and lightweight APIs for bootstrapping local development and test dependencies...'), repeats the 11-language list already covered by the description, and the References section re-summarizes each link. Not 3 because of this explanatory/definition padding; not 1 because it does not explain basic concepts throughout and is largely actionable.

2 / 3

Actionability

Provides fully executable, copy-paste-ready code for Java, Node.js, Python and Go, concrete package-install commands in a table, a CI workflow YAML, and specific wait-strategy recommendations per container. Not 2 because the examples are complete and runnable rather than pseudocode with missing details.

3 / 3

Workflow Clarity

A clear Step 1-6 sequence covers module selection, container declaration, wait strategy, framework wiring, networking and reuse; wait strategies act as explicit readiness validation before the test proceeds, and the Anti-patterns table provides error-recovery guidance. Not 2 because checkpoints (wait-for-ready) are explicit and the sequence is unambiguous.

3 / 3

Progressive Disclosure

No bundle files exist, so there is nothing to offload; the body is well-organized into clearly navigable sections (Step 1-6, CI integration, Anti-patterns, Limitations, References) with one-level-deep external reference links that are clearly signaled. Not 2 because organization and navigation are clear and no content is inappropriately inline that should be split, given the cross-language comparison purpose.

3 / 3

Total

11

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12

Passed

Description

100%

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

The description is specific, uses natural trigger terms, explicitly states both what it does and when to use it, and occupies a clear niche with low conflict risk. Voice is correctly third person ('Brings up', 'Wires').

DimensionReasoningScore

Specificity

Lists multiple concrete actions - 'Brings up real backing services...as throwaway containers', 'Wires the per-test container lifecycle, exposed-port -> host-port mapping, wait strategies (port / log / HTTP / SQL), Ryuk-based cleanup, container-to-container networks, and the (experimental) withReuse shortcut' - matching the anchor for listing multiple specific concrete actions. Not 2 because the action set is comprehensive and concrete rather than naming only a domain and a few actions.

3 / 3

Completeness

Clearly answers what ('Brings up real backing services...', 'Wires the per-test container lifecycle...') and when via an explicit 'Use when integration tests need a real Postgres / Redis / Kafka / Selenium / etc. and the team wants per-test isolation without hand-rolled docker-compose teardown.' clause. Not 2 because the 'when' is explicit, not merely implied.

3 / 3

Trigger Term Quality

Natural terms a user would say are well covered: 'integration tests', 'real Postgres / Redis / Kafka / Selenium', 'per-test isolation', 'docker-compose teardown', 'databases, message brokers, browsers'. Not 2 because it includes common variations and concrete technology names rather than only a few relevant keywords.

3 / 3

Distinctiveness Conflict Risk

A clear niche (Testcontainers, throwaway Docker containers driven from inside a test process) with distinct triggers and an explicit pointer to the alternative 'docker-compose-tests' skill, making conflict with other skills unlikely. Not 2 because the scope and triggers are specific rather than overlapping.

3 / 3

Total

12

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12

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.

Validation16 / 16 Passed

Validation for skill structure

No warnings or errors.

Reviewed

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