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404-page

Use when reviewing templates, rendered HTML, or shared components related to Create a custom 404 error page. Validate the final browser-facing markup, not just the source framework abstraction.

59

Quality

68%

Does it follow best practices?

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SecuritybySnyk

Passed

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tessl review fix ./skills/404-page/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

70%

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

The body is a well-organized, concise overview that appropriately defers detail to a single one-level-deep reference, and the simple review workflow is clear. Its main weaknesses are mild redundancy across the Check/Fix/Explain sections and a lack of any executable specifics in the body itself.

Suggestions

Remove the overlap between the intro paragraph and the Explain section, and state the soft-404/HTTP-404 requirement once rather than repeating it across Quick Reference, Check, Fix, and Explain.

Add at least one concrete executable check in the body (e.g., a curl command to confirm a 404 status code) so the actionability does not rely entirely on the reference file.

DimensionReasoningScore

Conciseness

The body is short and mostly lean, but the intro paragraph restates the Explain section and the soft-404/HTTP-404 point is repeated across Quick Reference, Check, Fix, and Explain, so it could be tightened.

2 / 3

Actionability

It gives concrete review guidance ('Confirm the route returns HTTP 404 and not a branded page with a 200 response', 'Flag exact elements, attributes, and routes'), but the body itself contains no executable commands or code, deferring all of that to the reference.

2 / 3

Workflow Clarity

This is a simple single-purpose review skill clearly organized into Check, Fix, Explain, and Code Review sections; per the simple-skills note, clear and well-organized single-purpose content can score 3 without a multi-step workflow.

3 / 3

Progressive Disclosure

The body is a concise overview that signals one one-level-deep reference ('see references/rule.md' for implementation details and code), and that bundle file exists, giving easy one-level navigation.

3 / 3

Total

10

/

12

Passed

Description

67%

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 clearly answers both what and when with an explicit 'Use when' trigger, but its action list is narrow and the trigger language is more technical than what users would naturally say. It is reasonably scoped to the 404 niche yet could still overlap with broader frontend review skills.

Suggestions

Add more concrete review actions beyond 'reviewing' and 'Validate' (e.g., 'check HTTP status codes, flag missing navigation/search, verify noindex markup') to lift specificity.

Include natural user-facing trigger variations such as '404', 'page not found', and 'custom error page' alongside the technical framing.

Sharpen distinctiveness by leading with the 404-specific checks rather than the generic 'reviewing templates/rendered HTML' phrasing that overlaps general frontend review skills.

DimensionReasoningScore

Specificity

Names the actions 'reviewing' and 'Validate' against templates, rendered HTML, and shared components, but these are only two actions with object variation rather than a comprehensive list of distinct concrete actions.

2 / 3

Completeness

It explicitly answers both 'what' ('Validate the final browser-facing markup, not just the source framework abstraction') and 'when' via an explicit 'Use when reviewing...' trigger clause.

3 / 3

Trigger Term Quality

'404 error page' is a natural term a user would say, but the rest of the triggers lean technical ('rendered HTML', 'browser-facing markup', 'source framework abstraction') and common variations like '404', 'page not found', or 'custom error page' are missing.

2 / 3

Distinctiveness Conflict Risk

It is scoped to the 404-page niche, but the 'reviewing templates, rendered HTML, or shared components' framing is generic frontend-review language that could overlap with other HTML/component review skills.

2 / 3

Total

9

/

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

metadata_version

'metadata.version' is missing

Warning

Total

15

/

16

Passed

Repository
thedaviddias/Front-End-Checklist
Reviewed

Table of Contents

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