CtrlK
BlogDocsLog inGet started
Tessl Logo

arktype

Arktype: runtime validation, discriminated unions with .merge()/.or(), spread keys. Use when mentioning arktype, type(), union types, command/event schemas.

72

Quality

88%

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

77%

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

The body is highly actionable and gives clear pattern-selection guidance, but it is somewhat long and redundant across overlapping union-composition patterns, and it keeps all detail inline in one large file rather than progressively disclosing it into separate reference files. Tightening the overlap and splitting long reference material would lift the weaker dimensions.

Suggestions

Collapse the three overlapping union patterns (.merge().or() chaining, spread-key, type.or() static) into a single comparison table or pick one recommended form, removing the redundant 'Why this pattern' and 'Why derive from constants' benefit tables that restate the same points.

Move the long detailed sections (e.g. 'type.enumerated()' and the Merge Behavior / Discriminant Detection reference material) into a bundled reference file under references/ and link to it from a concise overview, so the SKILL.md body progressively discloses rather than inlining everything.

Trim the prose between code blocks where the GOOD/BAD examples already make the point (e.g. the repeated explanation of why 'key?' beats 'string | undefined'), trusting the annotated examples to carry the guidance.

DimensionReasoningScore

Conciseness

The body is information-dense about arktype-specific semantics and assumes TypeScript competence, but it covers three overlapping union patterns (.merge().or() chaining, spread-key, type.or() static) plus redundant 'Why this pattern'/'Why derive from constants' tables that restate benefits, so it could be tightened rather than being fully lean (score 3).

2 / 3

Actionability

Multiple complete, executable TypeScript snippets with explicit GOOD/BAD contrasts (e.g. the type()-wrap and 'key?' optional sections) are copy-paste ready, matching the fully-executable anchor; not score 2 because the examples are real code, not pseudocode.

3 / 3

Workflow Clarity

Each pattern carries explicit 'Use when...' / 'Good for 2-3 variants' / 'For 4+ variants, prefer...' selection guidance, giving an unambiguous decision flow for a pattern-reference skill with no destructive or batch operations requiring validation checkpoints.

3 / 3

Progressive Disclosure

Sections are well-organized, but the skill is a single ~360-line monolithic file with no bundle files; the trailing References point to external repo paths and a GitHub URL rather than one-level-deep skill-internal reference files, so content that could be split out stays inline (score 2, not 3).

2 / 3

Total

10

/

12

Passed

Description

100%

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 concise, concrete, and clearly answers both what the skill does and when to use it, anchored to a specific library to avoid triggering for the wrong skill. It is a strong example of a well-formed skill description.

DimensionReasoningScore

Specificity

Quotes 'runtime validation, discriminated unions with .merge()/.or(), spread keys' list multiple concrete capabilities, matching the 'lists multiple specific concrete actions' anchor rather than the partial score-2 anchor.

3 / 3

Completeness

It states what ('Arktype: runtime validation, discriminated unions...') and gives an explicit 'Use when...' trigger, matching the score-3 anchor; not score 2 because the when clause is explicit rather than merely implied.

3 / 3

Trigger Term Quality

'Use when mentioning arktype, type(), union types, command/event schemas' covers natural terms a user would actually say for this domain, matching the good-coverage anchor rather than missing common variations at score 2.

3 / 3

Distinctiveness Conflict Risk

'Arktype' names a specific library with niche triggers (arktype, type()) unlikely to conflict with other skills, matching the clear-niche anchor; not score 2 since it is not merely 'somewhat specific'.

3 / 3

Total

12

/

12

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.

Repository
EpicenterHQ/epicenter
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.