define-errors

defineErrors from wellcrafted: variant factories, extractErrorMessage, InferErrors/InferError, call site patterns. Use when creating error types or reviewing error patterns.

Quality

85%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

Quality

Content

82%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 lean, executable, and well-structured with concrete code patterns covering the common cases. The main improvement area is trimming some codebase-specific rationale prose and optionally splitting long sections into reference files.

Suggestions

Tighten the "Why" prose in Avoid Parallel Envelopes and Whispering RPC sections to the minimum non-obvious rationale, moving extended justification to a reference file.

Consider extracting the exhaustive-switch and parallel-envelope conventions into a reference file so SKILL.md stays a concise overview with one-level-deep pointers.

Add a brief "When NOT to use this" pointer distinguishing variant construction from catch adaptation owned by error-handling, to reinforce the boundary already noted in the intro.

Dimension	Reasoning	Score
Conciseness	Dense, assumes TypeScript competence with no padding of concepts Claude already knows, but several codebase-specific "Why" prose blocks (Avoid Parallel Envelopes, Whispering RPC) could be tightened, fitting the efficient-with-minor-over-explanation 4 anchor.	4 / 5
Actionability	Fully executable, copy-paste-ready TypeScript examples cover the common cases (simple variant, structured fields, cause handling, multiple variants, domain errors, type extraction) with call sites shown.	5 / 5
Workflow Clarity	Core Rules provide a clearly numbered convention sequence and the exhaustive-switch guidance is well-sequenced; no destructive/batch validation pipeline is present so checkpoints are unwarranted, placing it at the clear-sequence-with-minor-gaps 4 anchor.	4 / 5
Progressive Disclosure	No bundle files exist; the body is organized into well-labeled sections with one-level sibling-skill references and no nested chains, but some longer rationale sections could live in separate reference files, fitting the good-structure-with-minor-gaps 4 anchor.	4 / 5
	Total	17 / 20 Passed

Description

87%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 is concise, third-person, and covers both what the skill does and when to invoke it with concrete trigger phrases. It carves out a clear niche with explicit boundaries against sibling skills.

Dimension	Reasoning	Score
Specificity	Lists several concrete capabilities ("variant factories, extractErrorMessage, InferErrors/InferError, call site patterns") but enumerates API surface names rather than multiple discrete action verbs, leaving minor coverage gaps versus the comprehensive 5 anchor.	4 / 5
Completeness	Explicitly answers both what (variant factories, extractErrorMessage, InferErrors/InferError, call site patterns) and when ("Use when creating error types or reviewing error patterns") with concrete trigger phrases.	5 / 5
Trigger Term Quality	Natural trigger phrases ("creating error types", "reviewing error patterns") would plausibly be said by a developer, but a few common synonyms or variations are missing, so it sits below the comprehensive 5 anchor.	4 / 5
Distinctiveness Conflict Risk	Clear niche (defineErrors error construction) with distinct triggers and explicit ownership boundaries against error-handling, logging, and services-layer, giving minimal conflict risk.	5 / 5
	Total	18 / 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/define-errors/SKILL.md
Commit: ecba024

Reviewed: 6 days ago

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