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create-skill

Guide for creating effective skills. This command should be used when users want to create a new skill (or update an existing skill) that extends Claude's capabilities with specialized knowledge, workflows, or tool integrations. Use when creating new skills, editing existing skills, or verifying skills work before deployment - applies TDD to process documentation by testing with subagents before writing, iterating until bulletproof against rationalization

Quality

74%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

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SecuritybySnyk

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./antigravity/skills/create-skill/SKILL.md

The canonical home for this skill is create-skill in NeoLabHQ/context-engineering-kit

SKILL.md
Quality
Evals
Security

Quality

Content

56%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 highly actionable with concrete templates, commands, and a well-sequenced creation workflow, but it badly needs an editor: the TDD framing is repeated across four or five sections, and much of the reference material contradicts the skill's own advice to live in separate files. A dangling reference to a non-existent persuasion-principles.md and internal numbering glitches further hurt organization.

Suggestions

Collapse the redundant TDD sections ("TDD Mapping for Skills", "The Iron Law", "RED-GREEN-REFACTOR for Skills", "Skill Creation Checklist", "The Bottom Line") into a single statement of the cycle plus one checklist — this alone would cut hundreds of tokens and lift conciseness toward anchor 4.

Move the CSO details, flowchart usage rules, code-example guidance, and anti-pattern catalogs into a references/ file (e.g. references/skill-authoring-guide.md) referenced one level deep, matching the progressive-disclosure structure the skill itself prescribes.

Fix the dangling "persuasion-principles.md" reference (either bundle the file or drop the citation), repair the broken "Discovery Workflow" numbering (1,3,4,5,6), and deduplicate the two "### 4." headings under Claude Search Optimization.

DimensionReasoningScore

Conciseness

The ~840-line body restates the TDD cycle four times ("TDD Mapping for Skills" table, "The Iron Law", "RED-GREEN-REFACTOR for Skills", "Skill Creation Checklist", "The Bottom Line"), explains concepts Claude already knows ("Skills are modular, self-contained packages..."), and has a broken "Discovery Workflow" numbered 1,3,4,5,6 plus two duplicate "### 4." headings. Matches anchor 2 (noticeably verbose, several padded/redundant sections); not 3 because the redundancy is pervasive rather than occasional.

2 / 5

Actionability

Provides concrete, executable guidance: a full SKILL.md template with YAML frontmatter, specific commands (`mkdir -p skills/<skill-name>`, `wc -w skills/path/SKILL.md`), checklists, and example user questions. Mostly executable per anchor 4; not 5 because the core testing methodology is delegated to a referenced external skill rather than shown, and some checklist items are unexecutable as written.

4 / 5

Workflow Clarity

"Skill Creation Process" Steps 1-6 are clearly sequenced with skip conditions, validation (Step 5), and iteration (Step 6), and the RED-GREEN-REFACTOR cycle supplies explicit feedback loops ("Re-test until bulletproof"). Not 5 because two competing workflow framings (the TDD cycle vs. the Step 1-6 process) coexist, and validation checkpoints are stated as unchecked checklist bullets rather than gated pass/fail steps.

4 / 5

Progressive Disclosure

No bundle files exist, yet the body references "persuasion-principles.md" and links an external graphviz conventions file — a dangling reference. Content is well-headered but monolithic: CSO details, flowchart rules, and anti-pattern reference material are inlined that the skill's own guidance says belongs in references files. Matches anchor 3 (some structure, content that should be separate is inline); not 2 because section headers do provide navigable structure.

3 / 5

Total

13

/

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 strong description that explicitly answers both what the skill does and when to use it, with concrete trigger phrases, natural keywords, and correct third-person voice. Its main weaknesses are a generic opening clause and a few missing search synonyms (e.g. "SKILL.md", "skill authoring").

DimensionReasoningScore

Specificity

Explicitly lists several actions — "create a new skill (or update an existing skill)", "verifying skills work before deployment", "testing with subagents", "iterating until bulletproof" — though the opener "Guide for creating effective skills" is generic. Matches anchor 4 (several specific actions, minor gaps); not 3 because more than 1-2 actions are named, not 5 because the actions are process-level rather than fully concrete.

4 / 5

Completeness

Both answered explicitly: what ("applies TDD to process documentation by testing with subagents before writing, iterating until bulletproof against rationalization") and when ("Use when creating new skills, editing existing skills, or verifying skills work before deployment"). Trigger guidance is explicit, voice is third-person ("This command should be used when..."), matching anchor 5.

5 / 5

Trigger Term Quality

Good natural-term coverage: "creating new skills", "editing existing skills", "verifying skills", "TDD", "subagents", "rationalization". Missing common variations like "SKILL.md", "write a skill", or "skill authoring", so it falls short of anchor 5's comprehensive synonym/extension coverage.

4 / 5

Distinctiveness Conflict Risk

Occupies a clear niche (skill authoring/testing) with distinct trigger phrases; minor overlap risk only with closely related skills it itself references (e.g. skill-best-practices commands). Not 5 because the generic "creating effective skills" domain could collide with other skill-writing skills.

4 / 5

Total

17

/

20

Passed

Validation

87%

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

Validation — 14 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

skill_md_line_count

SKILL.md is long (843 lines); consider splitting into references/ and linking

Warning

referenced_paths_exist

Referenced path issues: 12 missing

Warning

Total

14

/

16

Passed

Repository

NeoLabHQ/context-engineering-kit

Path

antigravity/skills/create-skill/SKILL.md

Reviewed

Table of Contents

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