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testland/jazzer-jvm-fuzzing

Author and run Jazzer - Code Intelligence's JVM coverage-guided fuzzer built on libFuzzer. Covers Maven / Gradle / standalone JAR installation, the @FuzzTest annotation (JUnit 5 integration), typed parameter mutation (String, primitives, byte[]), built-in JVM sanitisers (SSRF / path traversal / OS command injection / deserialization gadget / ReDoS), and the JAZZER_FUZZ=1 env var to switch between regression and fuzzing modes. Use for fuzz testing Java / Kotlin libraries - particularly effective against parsing, deserialization, and HTTP-handling code.

70

Quality

88%

Does it follow best practices?

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SecuritybySnyk

Passed

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Overview
Quality
Evals
Security
Files

Quality

Content

72%

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

The content is highly actionable with well-structured progressive disclosure and a clear spine/reference split. Weaknesses are conciseness (inline dated version and source attributions) and workflow clarity (implicit validation checkpoints for batch CI fuzzing).

Suggestions

Move the time-sensitive "0.22.1 was current at time of writing" note out of the main install flow — either drop the hard-coded version or isolate version-pinning guidance so the dated value does not penalize conciseness.

Trim repeated "Per Jazzer README / Per Jazzer docs" attribution phrasing; cite the source once in References and let the instructions stand on their own.

Add an explicit validate→fix→retry checkpoint to the CI / crash-triage loop in the spine (or clearly anchor it in the reference), so the batch smoke-fuzz workflow has a visible feedback loop rather than implicit validation.

DimensionReasoningScore

Conciseness

The body is mostly lean and code-forward, but inline time-sensitive notes ("0.22.1 was current at time of writing") and repeated "Per Jazzer README/docs" attribution phrasing could be tightened; the dated version is not isolated in a deprecated/old-patterns section, which the rubric penalizes.

2 / 3

Actionability

Provides fully executable Maven/Gradle snippets, complete Java @FuzzTest examples, exact bash commands (e.g. "JAZZER_FUZZ=1 mvn test -Dtest=ParserFuzzTest#fuzzDecode"), and a concrete flags table — copy-paste ready, matching the score-3 anchor.

3 / 3

Workflow Clarity

A clear Install→Author→Run sequence exists with a crash→reproducer→commit feedback path, but for batch/CI fuzzing operations the validation checkpoints are implicit or delegated to the reference file rather than explicit in the spine, capping this at 2 per the batch-operations scoring note.

2 / 3

Progressive Disclosure

SKILL.md acts as an overview spine delegating the full sanitiser catalogue and CI job to references/sanitisers-and-ci.md (a real, verified file) via clearly signaled one-level-deep markdown links, with sibling-skill and dispatcher pointers organized at the end — matching the score-3 anchor.

3 / 3

Total

10

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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, complete, and distinctive, with explicit "what" and "when" guidance and concrete natural trigger terms. Voice is correctly third person with no first/second-person usage to penalize.

DimensionReasoningScore

Specificity

Lists multiple concrete actions and features — "Author and run Jazzer", "Maven / Gradle / standalone JAR installation", "@FuzzTest annotation", "typed parameter mutation", "built-in JVM sanitisers", "JAZZER_FUZZ=1 env var to switch between regression and fuzzing modes" — matching the score-3 anchor for multiple specific concrete actions.

3 / 3

Completeness

Explicitly answers both "what" (author/run Jazzer with install, annotation, sanitisers, env var) and "when" via the explicit "Use for fuzz testing Java / Kotlin libraries - particularly effective against parsing, deserialization, and HTTP-handling code" clause, matching the score-3 anchor.

3 / 3

Trigger Term Quality

Includes natural terms a user would say — "fuzz testing", "Java / Kotlin libraries", "parsing, deserialization, and HTTP-handling code" — giving good coverage of common phrasings, though it leans somewhat on the product name "Jazzer".

3 / 3

Distinctiveness Conflict Risk

Occupies a clear niche (JVM coverage-guided fuzzer, Jazzer, @FuzzTest, JAZZER_FUZZ) with distinct triggers unlikely to fire for non-JVM or non-fuzzing skills, matching the score-3 anchor for a clear niche with distinct triggers.

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.

Validation16 / 16 Passed

Validation for skill structure

No warnings or errors.

Reviewed

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