CtrlK
BlogDocsLog inGet started
Tessl Logo

no-unchecked-indexed-access

Use when auditing tsconfig.json for missing safety flags, reviewing code that uses array index access in data processing pipelines, or investigating runtime undefined errors that TypeScript did not catch.

69

Quality

85%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

87%

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

A well-structured, lean instruction skill that defers detail to a single one-level reference and gives concrete auditing guidance. Its one gap is the absence of an explicit verify/re-check checkpoint in the Fix workflow for a batch operation.

Suggestions

Add an explicit verification step in Fix, e.g. 'Re-run tsc --noEmit and confirm no noUncheckedIndexedAccess errors remain before considering the fix complete.'

Show one minimal before/after snippet (unsafe arr[i] vs guarded access) in the Fix section to make the actionable guidance copy-paste ready.

DimensionReasoningScore

Conciseness

The body is lean — tight Quick Reference bullets and concise Check/Fix/Explain/Code Review sections that assume TypeScript competence; the brief intro paragraph earns its place by justifying the rule rather than padding, matching the lean-and-efficient anchor.

3 / 3

Actionability

For an instruction/audit skill the guidance is concrete and executable — 'Check whether noUncheckedIndexedAccess is enabled in tsconfig.json', 'scan for array index accesses (arr[0], arr[i])', and 'Enable noUncheckedIndexedAccess in tsconfig.json, then update... with an explicit undefined check or optional chaining' — so the absence of copy-paste code is not penalized per the code-vs-instruction scoring note.

3 / 3

Workflow Clarity

The Check/Fix/Explain/Code Review sections give a clear sequence, but this is a batch audit/review operation and the Fix step lacks an explicit verification checkpoint (e.g. re-run tsc to confirm no remaining flagged accesses), so per the feedback-loops note validation gaps cap this at anchor 2.

2 / 3

Progressive Disclosure

A short, well-organized overview body with a single clearly signaled one-level-deep reference to references/rule.md (a real file) and no nested references, matching the clear-overview-with-well-signaled-references anchor for a simple skill.

3 / 3

Total

11

/

12

Passed

Description

82%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong, specific trigger-focused description with excellent distinctiveness and natural trigger terms. Its main weakness is that the capability ('what it does') is implied through scenarios rather than stated explicitly alongside the 'when'.

Suggestions

Lead with an explicit capability clause before the triggers, e.g. 'Enables the noUncheckedIndexedAccess tsconfig flag and hardens array index access against undefined values. Use when...'

Add the common user phrasing 'out-of-bounds' / 'undefined is not a function' alongside 'runtime undefined errors' to broaden natural trigger coverage.

DimensionReasoningScore

Specificity

Lists multiple concrete actions — 'auditing tsconfig.json for missing safety flags', 'reviewing code that uses array index access', 'investigating runtime undefined errors' — tied to a specific config and language, matching the anchor for listing several specific concrete actions.

3 / 3

Completeness

The 'Use when' clause explicitly and richly answers when to use it, but the 'what does this do' is only implied through the scenario phrasing rather than stated as a capability, so it does not clearly answer both what and when as anchor 3 requires.

2 / 3

Trigger Term Quality

Natural terms a developer would say ('tsconfig.json', 'array index access', 'runtime undefined errors', 'TypeScript') give good trigger coverage; a user hitting a TS undefined error would naturally land here, clearing the anchor for good coverage of natural terms.

3 / 3

Distinctiveness Conflict Risk

A tight niche around the noUncheckedIndexedAccess flag and array-index-access bugs makes it unlikely to trigger for the wrong skill, matching the clear-niche anchor.

3 / 3

Total

11

/

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

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.