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arn-code-feature-spec

This skill should be used when the user says "feature spec", "arness code feature spec", "arn-code-feature-spec", "spec this feature", "help me spec", "design this feature", "feature design", "write a spec", "create a specification", "I have an idea for a feature", "let's flesh out this feature", "decompose feature", "spec XL feature", "resume spec", "continue spec", "finish my spec", "break down feature", or wants to iteratively develop a feature idea into a well-formed specification through guided conversation with architectural analysis. For XL features with decomposition hints, creates multiple sub-feature specs with full traceability. Produces specification documents capturing WHAT to build and WHY, which then feed into plan creation.

Quality

88%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

81%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.

An impressively rigorous workflow skill: fully concrete prompts, explicit flags and conditional branches, and best-in-class error handling with recovery paths for every failure mode. The two costs are token weight — meaningful duplication around sketch context and Step 5 finalization — and a main body long enough that some procedural detail belongs in the existing references structure.

Suggestions

Deduplicate the sketch-manifest capture logic: state it once (e.g., in a short 'Sketch context' subsection or reference file) and have Step 2 and the exploration-phase sketch section both point to it, instead of repeating the field list twice.

In Step 5, merge the two Sketch Reference population passages (numbered finalization actions and the no-draft fallback) into one description of the section's contents, referenced by both paths.

Move the per-agent context specifications in Step 3b (architect, UX, security specialist) into agent-invocation-guide.md, which already exists for agent-dispatch decisions, and keep only a summary table in the body.

DimensionReasoningScore

Conciseness

The body is mostly operational content Claude could not infer (conditional flows, exact prompts), but there is real repetition: sketch-manifest capture logic is spelled out twice (Step 2 sketch detection and "After a sketch session completes"), Sketch Reference population is stated twice in Step 5 (numbered finalization actions and the no-draft fallback list), and the per-agent context lists in Step 3b restate "Feature idea"/"Codebase context" fields for each agent. Fits 'mostly efficient but could be tightened' (3); not 4 because the duplicated blocks are non-trivial in size, and not 2 because nothing explains concepts Claude already knows.

3 / 5

Actionability

Guidance is copy-paste executable for a conversational skill: exact regex ("F-\\d{3}"), verbatim user prompts and AskUserQuestion option sets, fenced context templates (--- BEGIN USER EXPERTISE ---), named agents, concrete file paths, and a section-completeness table for the draft. This matches the fully-executable anchor; a 4 would require missing key details, which are absent gaps here.

5 / 5

Workflow Clarity

Steps 0-5 are clearly sequenced with explicit conditional branches (decomposition mode, security pre-check, UI detection, draft resume), a readiness checkpoint with a verbatim prompt ("I think we have enough to finalize..."), and a dedicated Error Handling section covering every failure mode with recovery loops (draft write fails -> fall back to in-conversation mode; update fails -> continue, reconcile at Step 5; draft deleted -> recreate from conversation). Matches the anchor with explicit validation steps and error-recovery feedback loops.

5 / 5

Progressive Disclosure

Four real reference files exist in references/ (greenfield-loading.md, xl-decomposition.md, feature-spec-template.md, agent-invocation-guide.md) and each is referenced from the body, one level deep and clearly signaled ("> Read ${CLAUDE_PLUGIN_ROOT}/... for the full loading sequence"). The detail is well split out of the main flow. Falls short of 5 because the ~480-line body itself inlines substantial material that could live in references (the full per-agent context specs in Step 3b, sketch detection/enrichment logic), leaving the overview heavier than the ideal clear-overview anchor.

4 / 5

Total

17

/

20

Passed

Description

91%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 strong description: explicit use-when clause with an unusually comprehensive set of natural trigger phrases, paired with a clear statement of the artifacts produced and how they feed downstream planning. The only weaknesses are slight overlap risk from generic phrases like "write a spec" and an action list that emphasizes outputs over the conversational process itself.

DimensionReasoningScore

Specificity

Concrete actions are named — "iteratively develop a feature idea into a well-formed specification through guided conversation with architectural analysis", "creates multiple sub-feature specs with full traceability", and "Produces specification documents capturing WHAT to build and WHY, which then feed into plan creation" — but the action list centers on spec production and gives less coverage of the intermediate behaviors (agent analysis, draft/resume handling). Fits 'several specific actions; minor gaps' (4) rather than the comprehensive coverage anchor (5), and clearly exceeds '1-2 concrete actions' (3).

4 / 5

Completeness

Explicitly answers both questions: 'when' via "This skill should be used when the user says ... or wants to iteratively develop a feature idea into a well-formed specification", and 'what' via the concrete outputs (specification documents, sub-feature specs with traceability, feeding into plan creation). Matches the anchor for concrete trigger phrases plus explicit what-and-when; a 4 would require the 'when' to be less explicit, which it is not.

5 / 5

Trigger Term Quality

Seventeen quoted trigger phrases including natural variations users would actually say ("I have an idea for a feature", "help me spec", "let's flesh out this feature", "resume spec", "continue spec", "finish my spec") plus the exact skill name "arn-code-feature-spec". This matches the comprehensive synonym-coverage anchor; nothing common is missing.

5 / 5

Distinctiveness Conflict Risk

The skill name trigger and ecosystem-specific terms ("arness code feature spec", "spec XL feature") give it a clear niche, but broadly applicable phrases like "write a spec", "design this feature", and "create a specification" could overlap with a sibling planning/spec-writing skill in the same plugin. Fits 'mostly distinct; minor overlap risk' (4) rather than 'clear niche with minimal conflict risk' (5).

4 / 5

Total

18

/

20

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.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

AppsVortex/arness

Path

plugins/arn-code/skills/arn-code-feature-spec/SKILL.md

Reviewed

Table of Contents

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