martinfrancois/java-streams
Help AI coding agents use Java Streams and Collectors well in new code, review, and cleanup without replacing one antipattern with another.
100
100%
Does it follow best practices?
Impact
100%
2.17xAverage score across 4 eval scenarios
Passed
No known issues
Quality
Discovery
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.
This is an excellent skill description that thoroughly covers what the skill does, when to use it, and includes comprehensive trigger terms. It lists specific antipatterns and stream operations that serve as both documentation and natural trigger keywords. The description is dense but purposeful, with no vague fluff or buzzwords.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | The description lists multiple specific concrete actions (write, review, refactor) and enumerates detailed antipatterns to avoid (materializing just to inspect, sorting before min/max, counting for existence, nested stream collections, unsafe null sorting, careless findFirst/findAny). This is highly specific about what the skill does. | 3 / 3 |
Completeness | Clearly answers both 'what' (write, review, refactor Java Stream and Collector code with best practices, avoiding specific antipatterns) and 'when' (explicit 'Use whenever' clause listing comprehensive trigger scenarios including specific stream operations and patterns). | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms a user would say: 'Java Stream', 'Collector', 'streams', 'collectors', 'primitive streams', 'Optional', 'map/flatMap/mapMulti', 'grouping', 'joining', 'distinct', 'sorted', 'limit', 'takeWhile/dropWhile', 'teeing', 'partitioningBy', 'summarizing', 'parallel stream'. These are exactly the terms a developer would use when asking for help. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive — narrowly scoped to Java Streams and Collectors specifically, with detailed enumeration of stream-specific operations and antipatterns. Unlikely to conflict with general Java skills or other language-specific skills due to the precise domain focus. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
100%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a high-quality skill that efficiently covers Java Streams best practices with concrete, actionable guidance. The numbered workflow with validation checkpoints, the goal-to-API mapping table, and the before/after code example demonstrate excellent structure. The progressive disclosure to reference files is well-organized, and the content respects Claude's intelligence by avoiding basic explanations.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is dense and efficient. It assumes Claude knows Java, streams, and collectors. Every section adds specific, non-obvious guidance (antipattern replacements, API selection tables, ordering/mutability nuances). No wasted tokens explaining what streams are or how lambdas work. | 3 / 3 |
Actionability | Provides a concrete goal-to-API mapping table, executable before/after code examples, specific rules (e.g., 'do not create an ArrayList and mutate it from forEach'), and precise API recommendations per Java version. The guidance is specific enough to be directly applied. | 3 / 3 |
Workflow Clarity | The 0-8 numbered workflow is clearly sequenced: check Java baseline → pick terminal → flatten → use primitive streams → choose collectors → preserve ordering/mutability → keep imperative when clearer → verify. Step 8 includes explicit validation (empty inputs, nulls, parallel-safety, re-scan). The hard-stops scan serves as a feedback loop for error recovery. | 3 / 3 |
Progressive Disclosure | Clean reference table at the top with three clearly-signaled one-level-deep references (hard-stops.md, stream-examples.md, java-stream-api.md). The SKILL.md serves as an actionable overview while deferring detailed examples and API compatibility tables to reference files. Navigation is straightforward. | 3 / 3 |
Total | 12 / 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.
Validation — 11 / 11 Passed
Validation for skill structure
No warnings or errors.
Reviewed
Table of Contents