arktype

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

Quality

84%

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Securityby

Passed

No findings from the security scan

Quality

Content

78%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.

A dense, highly actionable pattern catalog with executable code, correct/incorrect contrasts, and precise failure modes throughout. Its main weakness is monolithic structure: everything is inline in one file with no progressive disclosure, and one reference points outside the bundle.

Suggestions

Split lower-frequency material (Workspace Field Expressions, type.enumerated() derivation details, Merge Behavior semantics) into a references/ file, keeping SKILL.md as the overview of the three composition patterns.

Fix or remove the '.agents/skills/typescript/SKILL.md' reference — it is not part of this bundle and cannot be resolved; replace with a real file in references/ if the material matters.

Consolidate the duplicated union-composition guidance (chaining pattern section, '.or() Chaining vs type.or() Static', and the anti-pattern) into one decision table to trim redundancy.

Dimension	Reasoning	Score
Conciseness	Almost every section is code plus constraints with no padding about what arktype is; assumes Claude's competence. Minor trimmable redundancy (chaining vs type.or() guidance appears in three sections, plus a brief TypeScript value/type-space explanation) keeps it at anchor 4 rather than 5.	4 / 5
Actionability	Every pattern ships copy-paste-ready TypeScript with good/bad contrasts, anti-patterns, and exact error messages (e.g., 'ParseError: Spread operator may only be used as the first key', 'Expected an expression before []'). Fully executable and covering the common cases matches anchor 5.	5 / 5
Workflow Clarity	Pattern-selection guidance is clearly sequenced (recommended base.merge(type.or(...)) first, chaining for 2-3 variants, spread key as alternative, explicit 4+ variant threshold) with failure modes stated. No explicit validation/recovery checkpoints, but no destructive or batch operations exist; fits anchor 4 rather than 5's explicit feedback loops.	4 / 5
Progressive Disclosure	No bundle files exist (no references/, scripts/, or assets/), so all ~370 lines are inlined in SKILL.md, including sections like 'Workspace Field Expressions' and type.enumerated() details that could live in reference files. The References section points to '.agents/skills/typescript/SKILL.md', which is not part of this bundle and cannot be verified. Well-organized headers, but anchor 3 (content that should be separate is inline) fits better than 4.	3 / 5
	Total	16 / 20 Passed

Description

83%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.

A terse, well-targeted description with concrete capabilities and an explicit trigger clause naming the library. It would reliably fire on arktype mentions, though slightly broader synonym coverage and a fuller capability list would strengthen it.

Dimension	Reasoning	Score
Specificity	Names the domain plus three concrete capability areas ('runtime validation, discriminated unions with .merge()/.or(), spread keys'), but coverage is not comprehensive — naming conventions and type.enumerated() from the body are omitted. Fits anchor 4 (several specific actions, minor gaps) better than 3 (only 1-2 actions) or 5 (comprehensive).	4 / 5
Completeness	Explicitly answers both what ('runtime validation, discriminated unions with .merge()/.or(), spread keys') and when ('Use when mentioning arktype, type(), union types, command/event schemas') with concrete trigger phrases, matching anchor 5. Not 4 because the 'when' clause is explicit and trigger-specific rather than generic.	5 / 5
Trigger Term Quality	Triggers include the library name and natural phrases ('arktype, type(), union types, command/event schemas'), but miss common synonyms like 'schema validation' or 'runtime type checking'. Good coverage with a few natural terms missing matches anchor 4, not 5's comprehensive synonym coverage.	4 / 5
Distinctiveness Conflict Risk	'arktype' is a distinct niche trigger, but 'union types' and 'runtime validation' could overlap with generic TypeScript or validation-library skills. Minor overlap risk with closely related skills matches anchor 4; the library-name trigger keeps it above anchor 3.	4 / 5
	Total	17 / 20 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository: EpicenterHQ/epicenter
Path: .agents/skills/arktype/SKILL.md
Commit: f9441c8

Reviewed: 3 days ago

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