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service-worker

Use when auditing repeat-visit performance, adding offline support, or evaluating PWA readiness for a web application.

52

Quality

59%

Does it follow best practices?

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SecuritybySnyk

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tessl review fix ./skills/service-worker/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

71%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 well-structured as an overview with excellent progressive disclosure to a real, substantive reference file, and the lifecycle workflow is clearly sequenced. Its weaknesses are mild duplication of the reference's 'Why It Matters' paragraph and no inline executable code, leaving the body's own guidance at the conceptual level.

Suggestions

Add a minimal inline registration snippet (3-5 lines) so the body's most common action is executable without opening the reference, lifting actionability.

Make the Check section concrete — e.g. 'Open DevTools > Application > Service Workers' or 'curl the page and inspect the SW-Related headers' — so verification is a real command rather than a description.

Replace the duplicated intro paragraph with a one-line purpose statement, since the full 'Why It Matters' rationale already lives in references/rule.md.

DimensionReasoningScore

Conciseness

The body is lean — terse Quick Reference bullets and short Check/Fix/Explain/Code Review sections — but the intro paragraph ('act as a programmable network proxy... cut load times on repeat visits by 50-90 %') is duplicated verbatim in references/rule.md's 'Why It Matters', matching anchor 4 ('minor instances of over-explanation that could be trimmed') rather than 5.

4 / 5

Actionability

Concrete directions exist ('Choose a caching strategy (cache-first, network-first, stale-while-revalidate) per resource type'; 'Flag missing install/activate lifecycle handlers, absent cache-versioning, missing fetch handlers') but the body contains no executable code or commands — all implementation is deferred to the reference, matching anchor 3 ('some concrete guidance but incomplete'). Not 4 because nothing in the body is directly executable; not 2 because the named strategies and specific review flags go beyond high-level hints.

3 / 5

Workflow Clarity

The Quick Reference lists steps in correct service-worker lifecycle order (register → install/pre-cache → choose strategy → activate cleanup) and the Check section acts as a verification checkpoint, matching anchor 4 ('clear sequence with most checkpoints present; minor validation gaps'). Not 5 because there is no explicit post-fix verification or error-recovery loop.

4 / 5

Progressive Disclosure

The body is a short overview with a clearly signaled, verified one-level-deep reference ('For full implementation details, code examples, and framework-specific guidance, see references/rule.md'), and that file exists and carries the bulk implementation content — matching anchor 5 ('clear overview with well-signaled one-level-deep references; easy navigation').

5 / 5

Total

16

/

20

Passed

Description

47%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 has strong, explicit trigger coverage for the PWA/offline domain but omits any statement of what the skill does, capping completeness and specificity low. It also misses the term 'service worker' itself, the most natural trigger keyword.

Suggestions

Add a 'what' clause before the 'Use when' clause, e.g. 'Registers a service worker and implements caching strategies for static assets and offline fallback. Use when...' — this addresses both completeness and specificity.

Include 'service worker' and 'caching' as trigger keywords, since users asking about service workers would not naturally say 'repeat-visit performance' or 'PWA readiness'.

Consider narrowing 'auditing repeat-visit performance' to something like 'auditing service-worker caching' to reduce overlap with general web-performance skills.

DimensionReasoningScore

Specificity

The description names the domain scenarios ('auditing repeat-visit performance', 'adding offline support', 'evaluating PWA readiness') but never states what the skill actually does — there is no concrete action like 'register a service worker' or 'implement caching strategies', matching the anchor 'names the domain but actions are minimal or generic'. It is not a 3 because no 1-2 concrete skill capabilities are listed, only usage triggers.

2 / 5

Completeness

The 'when' is explicit with three concrete triggers, but the 'what' is entirely absent — structurally identical to the anchor-2 example 'Use when working with documents' ('only when is present without what'). It cannot be a 3 because even a weakly implied 'what' is missing.

2 / 5

Trigger Term Quality

Natural phrases users would say are present ('offline support', 'PWA readiness', 'repeat-visit performance'), but the single most natural keyword — 'service worker' — plus 'caching' are missing, matching anchor 4 ('good keyword coverage; a few natural terms missing') rather than 5's comprehensive synonym coverage.

4 / 5

Distinctiveness Conflict Risk

'Offline support' and 'PWA readiness' carve a clear niche with minimal conflict risk, but 'auditing repeat-visit performance' could overlap with general web-performance skills, matching anchor 4 ('mostly distinct; minor overlap risk with closely related skills') rather than 5.

4 / 5

Total

12

/

20

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.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

metadata_version

'metadata.version' is missing

Warning

Total

15

/

16

Passed

Repository
thedaviddias/Front-End-Checklist
Reviewed

Table of Contents

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