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cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-*.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating user timing marks.

68

Quality

82%

Does it follow best practices?

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SecuritybySnyk

Low

Low-risk findings worth noting

SKILL.md
Quality
Evals
Security

Quality

Content

65%

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

A highly actionable, code-rich skill with clear procedures for both cpuprofile and trace analysis, but it is long and repetitive, lacks validation/backup checkpoints around its destructive in-place reformat step, and is monolithic with a dangling external reference.

Suggestions

De-duplicate the repeated file-size check, reformat step, 400MB threshold, and --max-old-space-size guidance: state the shared handling once and reference it from both file-type procedures.

Add a backup/confirm checkpoint before the in-place reformat (fs.writeFileSync(profilePath, ...)) and an explicit validate->retry loop, or drop the destructive reformat step.

Move the large buffer-parsing and phase/category reference tables into reference files under references/ and link to them one level deep; remove or actually create the referenced parseSnapshot.ts.

DimensionReasoningScore

Conciseness

The body is largely lean and code-driven and does not over-explain basics, but it is long (~515 lines) with notable redundancy — the file-size check, reformat step, 400MB threshold, and --max-old-space-size flag are repeated across Part 1, Part 2, and 'Handling Huge Files'. It could be tightened, matching the 'mostly efficient but could be tightened' anchor.

2 / 3

Actionability

Provides extensive fully executable JavaScript (parseProfileFromBuffer, parseTraceFromBuffer, event-filtering queries) with concrete thresholds (e.g. >50ms long tasks, >10ms function calls) and specific node commands, making it copy-paste ready.

3 / 3

Workflow Clarity

Both file types have clear numbered procedures and report outputs, and the size-check-before-parse guard is concrete, but the in-place reformat (fs.writeFileSync overwriting the original file) lacks a backup/confirm checkpoint and there is no validate→fix→retry feedback loop. The rubric caps destructive/batch workflows without validation at 2.

2 / 3

Progressive Disclosure

It is a well-organized but monolithic single file with no bundle files, and content that could be split (buffer parsing, full phase/category tables) is inline. It also references 'parseSnapshot.ts', which does not exist in references/scripts/assets — a dangling reference — matching the 'some structure, content that should be separate is inline' anchor.

2 / 3

Total

9

/

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.

A strong, specific description that names concrete analysis actions and provides an explicit 'Use when' trigger list covering natural user phrasings. It clearly states both what the skill does and when to use it, with low conflict risk.

DimensionReasoningScore

Specificity

Lists multiple concrete actions ("Analyze V8/Chrome CPU profiles", "investigating slow functions", "comparing code paths", "finding bottlenecks", "analyzing layout/paint/rendering") rather than vague language, matching the anchor for naming several specific actions.

3 / 3

Completeness

Explicitly answers what ("Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-*.json)") and when (an explicit "Use when:" clause listing triggers), matching the anchor for clearly answering both what AND when.

3 / 3

Trigger Term Quality

Includes natural user phrasings such as "profiling performance", "investigating slow functions", "finding bottlenecks", and "comparing code paths" that a user would naturally say, giving good trigger coverage.

3 / 3

Distinctiveness Conflict Risk

Targets a clear niche (V8/Chrome CPU profiles and DevTools trace files) with distinct, domain-specific triggers unlikely to fire for unrelated skills.

3 / 3

Total

12

/

12

Passed

Validation

93%

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

Validation15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

skill_md_line_count

SKILL.md is long (518 lines); consider splitting into references/ and linking

Warning

Total

15

/

16

Passed

Repository
posit-dev/positron
Reviewed

Table of Contents

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