BC 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.
The skill parses V8 heap snapshots to hunt memory leaks. Promises snapshot comparison, retainer-path lookup, and analysis scripts. Contains seven files: three TypeScript helpers (comparison, retainer search, parsing) and one Node.js streaming script. Sandbox confirms scripts stay within their directories; no critical issues found.
Code quality scores 84, but process score of 54 signals fragile logic. Never tested against actual models. For real heap snapshots (hundreds of MB), verify how the streaming helper scales. If you debug Node.js memory regularly, install it—the tool is purpose-built. For a one-off investigation, Chrome DevTools does the job faster.
Analyze V8 heap snapshots to investigate memory leaks and retention issues.
As a process C 54/100 · Has gaps — weak spots: result and completion, when it triggers, inputs and preconditions
How to improve
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 0
✓ No critical or high findings
Files scanned: 6. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
✓ No remarks against the Agent Skills spec
Process rating: all ten parameters 54/100
- 0Result and completion. Does not say what the result is
- 0Inputs and preconditions. Does not say what the process needs to start
- 0Progress reporting. Says nothing while it works
- 20When it triggers. No condition that starts the skill
- 60Tools and files. Uses tools (node) that frontmatter does not declare
- 85Steps. 33 steps, 1 vague phrases
- 100Failures and branches. 2 branches, has a failure section
- 100Consistency. Name and required fields are in place
- 100Execution cost. Instruction body is 2855 tokens
- 100Running it twice. Mutating operations check current state
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +5Description has no quoted example phrases that should trigger the skill
- +4Description does not say when NOT to use the skill (false activations)
- +3Output format is not stated: the model decides each time
- +1No license
- +2Single-language instructions
- +3Description length 315: enough signal without eating the budget
- +4Structure: 16 headings
- +3Step-by-step instructions: 33 items
- +4Has examples (8 code blocks)
Quality base 70; lint remarks subtract, signals add up to 100. Result: 84.
In the sandbox The scripts kept to themselves
The skill's scripts were run in a throwaway machine: no network, fake keys in the home directory, a tracer watching. We wrote down what they did. Reaching for the network or for secrets caps the technical grade at C; a quiet run adds no points.
Запущено 4 скрипта; каждому дали двадцать секунд, поддельный домашний каталог с ключами и сеть, в которой ничего нет.
helpers/compareSnapshots.ts | ничего за пределами своей папки |
helpers/findRetainers.ts | ничего за пределами своей папки |
helpers/parseSnapshot.ts | ничего за пределами своей папки |
helpers/streamSnapshot.mjs | ничего за пределами своей папки |
3 Oct 2026