125-java-concurrency

Use when you need to apply Java concurrency best practices — including thread safety fundamentals, ExecutorService thread pool management, concurrent design patterns like Producer-Consumer, asynchronous programming with CompletableFuture, immutability and safe publication, deadlock avoidance, virtual threads, structured concurrency, scoped values, backpressure, cancellation discipline, and observability for concurrent systems. This should trigger for requests such as Review Java code for concurrency; Review Java code for thread safety; Fix race conditions in Java concurrency code; Choose ExecutorService or virtual threads in Java; Improve synchronization and shared mutable state handling; Apply structured concurrency for related Java subtasks. Part of Plinth Toolkit

Quality

86%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

Quality

Content

81%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.

A well-structured, concise SKILL.md body with strong workflow gating and clean progressive disclosure to a single verified reference. Main weakness is that no executable concurrency code lives in the body itself and some sections duplicate the description.

Suggestions

Trim the 'When to use this skill' section, which duplicates the frontmatter description's trigger phrases, to save tokens.

Add one or two short inline code snippets (e.g. a virtual-thread executor or bounded-queue ExecutorService) so the body is actionable without opening the reference.

Consider merging the 'What is covered' list with the 'Scope' line to reduce redundancy with the description.

Dimension	Reasoning	Score
Conciseness	The body is lean and assumes Claude's knowledge, with a tight bulleted coverage list and short workflow; the only mild padding is the 'What is covered' list partly mirroring the description and the 'When to use this skill' section duplicating trigger phrasing.	4 / 5
Actionability	Concrete executable commands (`./mvnw compile`, `mvn clean verify`) and a named reference file are given, but the body itself offers no inline code examples for the concurrency patterns, deferring all runnable code to the reference.	4 / 5
Workflow Clarity	A clear 4-step sequence with an explicit pre-change compile gate ('stop immediately if compilation fails') and a post-change `mvn clean verify` validation checkpoint, satisfying the feedback-loop expectation for batch/destructive edits.	5 / 5
Progressive Disclosure	Body is an overview pointing to a single one-level-deep reference (references/125-java-concurrency.md, verified present) with a clearly signaled link; the inlined coverage list is reasonable but the 'When to use' section duplicates the description rather than being trimmed.	4 / 5
	Total	17 / 20 Passed

Description

91%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 rich, specific description that clearly conveys both scope and trigger conditions, with strong concrete capability listing and low conflict risk. Minor trigger-term synonym coverage could be broadened, but it otherwise exemplifies a high-quality skill description.

Dimension	Reasoning	Score
Specificity	Lists many concrete capabilities — 'thread safety fundamentals', 'ExecutorService thread pool management', 'Producer-Consumer', 'CompletableFuture', 'virtual threads', 'structured concurrency', 'ScopedValue', 'backpressure', 'cancellation discipline' — covering the domain comprehensively.	5 / 5
Completeness	Explicitly answers both 'what' (the enumerated concurrency practices) and 'when' (a 'Use when you need to apply...' clause plus concrete 'should trigger for requests such as' examples).	5 / 5
Trigger Term Quality	Includes natural trigger phrases ('Review Java code for concurrency', 'Fix race conditions in Java concurrency code', 'Choose ExecutorService or virtual threads in Java'), but misses common synonyms/extensions like 'multi-threaded', 'thread-safe', or '.java' file references.	4 / 5
Distinctiveness Conflict Risk	Narrowed to Java concurrency with highly specific triggers (virtual threads, StructuredTaskScope, ScopedValue); low overlap risk with non-Java or non-concurrency skills.	5 / 5
	Total	19 / 20 Passed

Validation

100%

Warnings & errors only

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: jabrena/plinth
Path: skills/125-java-concurrency/SKILL.md
Commit: 77b8825

Reviewed: about 23 hours ago

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