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testland/cold-start-budget-reference

Pure-reference catalog of latency budgets across serverless runtimes: cold starts AND timeouts. Covers AWS Lambda's three-phase cold start (Init: download+unzip+runtime-bootstrap; Init code: imports + module load; Invoke: handler execution), Cloudflare Workers' isolate model (sub-millisecond cold starts via V8 isolates per developers.cloudflare.com), Vercel Edge Runtime, Lambda SnapStart for JVM (snapshot-restore for Java), and provisioned-concurrency trade-offs, plus Lambda timeout + billing budgets in references/timeout-budgets.md (the 15-minute hard limit, getRemainingTimeInMillis, per-ms billing, memory-CPU scaling, the API Gateway 29s / SQS visibility-timeout integration cascade). Use when designing latency or timeout budgets, choosing a runtime, sizing memory, or auditing cold-start variance in production.

71

Quality

89%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

Overview
Quality
Evals
Security
Files

Quality

Content

85%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 content is a well-structured, actionable reference with a clear sequenced workflow, explicit validation checkpoints, and clean progressive disclosure into a verified reference file. The only room for improvement is light trimming of background explanations Claude already knows.

DimensionReasoningScore

Conciseness

The body is dense, table-driven, and largely free of padding, though it re-explains a few concepts Claude already knows (the three-phase cold-start breakdown, the isolate model) that could be trimmed slightly.

4 / 5

Actionability

Provides concrete per-runtime ranges, quantified mitigations ($30-300, <50MB zipped), executable lazy-import Python, and named hooks/metrics (beforeCheckpoint/afterRestore, CloudWatch Init Duration, getRemainingTimeInMillis); minor gaps are that figures are typical ranges rather than exact thresholds.

4 / 5

Workflow Clarity

The 6-step 'How to use' is explicitly sequenced with measurement checkpoints and a feedback loop ('Re-measure after each change and confirm the p99 tail moved'), reinforced by a 'Testable behaviours' checklist and a gated worked example, matching the anchor 5 of clear sequence with explicit validation and error-recovery.

5 / 5

Progressive Disclosure

The body is an overview that defers timeout/billing detail to the one-level-deep references/timeout-budgets.md (a real, verified file), with clearly signaled links in both a dedicated section and the References list and well-organized section headers throughout.

5 / 5

Total

18

/

20

Passed

Description

87%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 comprehensive, explicit about both purpose and trigger conditions, and occupies a distinctive niche. Its only weakness is a reference-catalog framing that names topics more than it leads with concrete actions, keeping specificity just below the top anchor.

Suggestions

Lead the description with concrete verbs (e.g., 'Look up, compare, and budget serverless cold-start and timeout latencies') before the catalog of covered runtimes to lift specificity to anchor 5.

Add a couple of natural synonyms or file/runtime tokens (e.g., 'p99 tail', 'provisioned concurrency', 'Java/Go/Rust') that users would say verbatim when reaching for this skill.

DimensionReasoningScore

Specificity

Catalogs many concrete, named items (SnapStart snapshot-restore, provisioned-concurrency trade-offs, getRemainingTimeInMillis, per-ms billing, API Gateway 29s cascade) but frames them as a reference catalog rather than leading with concrete verbs, leaving it just shy of the fully action-led anchor 5.

4 / 5

Completeness

Explicitly states both what ('Pure-reference catalog of latency budgets across serverless runtimes: cold starts AND timeouts') and when ('Use when designing latency or timeout budgets, choosing a runtime, sizing memory, or auditing cold-start variance in production'), in third person, matching the anchor 5 example.

5 / 5

Trigger Term Quality

Natural phrases users say are present ('Use when designing latency or timeout budgets, choosing a runtime, sizing memory, or auditing cold-start variance') with good coverage of 'cold start', 'latency budget', and 'runtime', though a few synonyms or file/runtime extensions are absent.

4 / 5

Distinctiveness Conflict Risk

Occupies a clear niche (serverless cold-start and timeout latency budgets) with distinct, specialized triggers unlikely to fire for unrelated skills.

5 / 5

Total

18

/

20

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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