heap-snapshot-analysis

Analyze V8 heap snapshots to investigate memory leaks and retention issues. Use when given .heapsnapshot files, asked to compare before/after snapshots, asked to find what retains objects, or investigating why objects survive GC. Provides snapshot parsing, comparison, retainer-path helpers, and scratchpad scripts.

Quality

89%

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Securityby

Passed

No findings from the security scan

Quality

Content

78%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.

The body is highly actionable with concrete executable code and commands, and the workflow is a clear four-step sequence with useful error-recovery guidance. Its main weakness is progressive disclosure: the SKILL.md imports from and links to helper/scratchpad files that are not present in the bundle, leaving the skill non-functional as packaged.

Suggestions

Ship the referenced helper files (parseSnapshot.ts, streamSnapshot.mjs, compareSnapshots.ts, findRetainers.ts) in a helpers/ bundle directory so the import examples actually resolve.

Add an explicit validation checkpoint to the workflow (e.g., verify the parsed graph/edge counts against snapshot.meta before running comparison or retainer analysis) to support a verify-fix-retry loop.

Tighten the 'Useful tricks' bullet list and the approximation-boundaries discussion, or move that detail into a reference file that is actually bundled, to improve token efficiency.

Dimension	Reasoning	Score
Conciseness	Mostly efficient and specialized (V8 format, VS Code retention patterns, false retainers) without explaining basics Claude already knows, but the 10-bullet 'Useful tricks' list and the approximation-boundaries discussion are instances that could be trimmed, keeping it just below the lean/5 anchor.	4 / 5
Actionability	Provides copy-paste-ready code for parseSnapshot/compareSnapshots/findRetainerPaths/streamSnapshot with concrete parameters (maxPaths: 5, maxDepth: 25) and exact bash commands with flags (node --max-old-space-size=24576), covering the common analysis cases.	5 / 5
Workflow Clarity	A clear four-step sequence (Parse → Compare → Find Retainers → Write Scripts) with error-recovery guidance (ERR_FS_FILE_TOO_LARGE → switch to streaming), but no explicit validation checkpoints or verify-fix-retry feedback loops in the main workflow, capping it below 5.	4 / 5
Progressive Disclosure	Sections are well-organized and references are clearly signaled with markdown links, but every referenced bundle path (helpers/parseSnapshot.ts, streamSnapshot.mjs, compareSnapshots.ts, findRetainers.ts, scratchpad/) is absent from the bundle, so the one-level-deep references do not resolve and the skill is incomplete as shipped; substantial specialized content is also inlined.	3 / 5
	Total	16 / 20 Passed

Description

100%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.

The description is exemplary: third-person voice, a concrete 'Use when...' trigger clause with the file extension, multiple specific actions, and a distinct niche that minimizes conflict risk. It clearly answers both what the skill does and when to invoke it.

Dimension	Reasoning	Score
Specificity	Lists multiple concrete actions — 'Analyze V8 heap snapshots', 'investigate memory leaks and retention issues', 'compare before/after snapshots', 'find what retains objects', and 'snapshot parsing, comparison, retainer-path helpers' — giving comprehensive coverage of the skill's capabilities.	5 / 5
Completeness	Explicitly answers both 'what' (analyze snapshots, investigate leaks/retention, provides parsing/comparison/retainer helpers) and 'when' via a concrete 'Use when given .heapsnapshot files, asked to compare...asked to find what retains objects, or investigating why objects survive GC' trigger clause.	5 / 5
Trigger Term Quality	Covers natural phrases users would say ('compare before/after snapshots', 'find what retains objects', 'why objects survive GC', 'memory leaks') plus the file extension '.heapsnapshot files', matching the comprehensive-coverage anchor.	5 / 5
Distinctiveness Conflict Risk	Occupies a clear niche (V8 heap snapshot analysis) with distinct triggers tied to '.heapsnapshot files' and retention/GC concepts, making conflict with other skills minimal.	5 / 5
	Total	20 / 20 Passed

Validation

93%

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 — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
relative_links	Relative link issues: 5 missing	Warning

	Total	15 / 16 Passed

Repository: posit-dev/positron
Path: .github/skills/heap-snapshot-analysis/SKILL.md
Commit: 061594d

Reviewed: 2 days ago

Table of Contents

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