Skill Creator
A guide for developing high-quality, token-efficient agent skills with built-in testing and evaluation standards.
Install
mkdir -p .claude/skills/skill-creator-ntluong95 && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/13837" && unzip -o skill.zip -d .claude/skills/skill-creator-ntluong95 && rm skill.zipInstalls to .claude/skills/skill-creator-ntluong95
Activation
This is the description your AI agent reads to decide when to run this skill — the better it matches your request, the more reliably it fires.
Standards for creating, testing, and optimizing Agent Skills. Use when creating, improving, catching regressions, measuring trigger rates, or writing eval cases for any skill.Key capabilities
- →Define mandatory frontmatter for skill metadata.
- →Implement a three-level loading system for skill content.
- →Write imperative guidelines using verbs and abbreviations.
- →Adhere to strict size limits for `SKILL.md` and code blocks.
- →Follow strict formatting rules for anti-patterns.
- →Create evaluation cases and design trigger queries for skills.
How it works
The skill provides standards and guidelines for creating, testing, and optimizing agent skills, focusing on token economy, progressive loading, and strict formatting rules. It includes a process for validation and iteration.
Inputs & outputs
When to use Skill Creator
- →Create a new agent skill
- →Write evaluation cases for skills
- →Optimize skill documentation
- →Catch skill regressions
About this skill
Agent Skill Creator Standard
Priority: P0 (CRITICAL)
Strict guidelines for High-Density Agent Skills. Maximize info/token ratio.
Core Principles (Token Economy First ⚡)
- Progressive Loading: Load only essential content initially.
- Lazy References: Move detailed examples to
references/. - Imperative Compression: Use verbs, abbreviations, bullet points.
- Context Limits: Cursor(~100k), Claude(~200k), Windsurf(~32k).
Three-Level Loading System
- Metadata: Triggers → AGENTS.md index (Proactive Activation)
- SKILL.md: Body < 100 lines → Core guidelines (When triggered)
- Resources:
references/,scripts/,assets/→ Deep knowledge (On-demand)
Writing Rules
- Imperative: Start with verbs. "Use BLoC" not "You should use BLoC".
- Token Economy: Skip articles. Use standard abbreviations. Bullets > paragraphs.
- Structure:
- Mandatory Frontmatter (YAML: name, description, metadata labels & triggers).
- Priority: P0 (Critical), P1 (Standard), P2 (Optional).
- Guidelines: Imperative Do's.
- Anti-Patterns: Strict format Don'ts.
- References: Links to lazy-loaded files.
Strict Size Limits
| Element | Limit | Action if Exceeded |
|---|---|---|
| SKILL.md total | 100 lines | Extract to references/ |
| Inline code block | 10 lines | Extract to references/ |
| Anti-pattern item | 15 words | Compress to imperative |
| Tables | 8 rows | Extract to references/ |
Strict Formatting Rules
- Anti-Patterns:
**No X**: Do Y[, not Z]. [Context <= 15 words]- Example:
**No Logic in Builder**: Perform calculations in BLoC, not UI.
- Example:
- No Redundancy: Do not repeat frontmatter descriptions.
- Oversized Skills: If SKILL.md >100 lines, extract step-by-step guides and complex scenarios to
references/. - Nested Formatting: Avoid
**Bold**: \More Bold``.
Test, Measure & Iterate
After writing a skill draft, validate it before shipping:
- Write eval cases: Create
evals/evals.jsonwith 2–3 realistic prompts (see testing.md). - Design trigger queries: Generate 8–10 should-trigger and 8–10 should-not-trigger queries to measure description accuracy.
- Optimize description: Make it "pushy" — list explicit trigger contexts, not just what it does.
- Catch regressions: Snapshot the skill before editing; compare before/after outputs for existing test cases.
- Iterate: Re-run evals after each change; stop when trigger rate ≥ 80% on held-out queries.
See Testing, Trigger Rate & Regression Guide for eval schema, query design rules, and regression protocol.
Resources & Deep Knowledge
When not to use it
- →When the task does not involve creating, testing, or optimizing agent skills.
- →When ignoring token economy principles for skill content.
- →When not adhering to the three-level loading system.
Limitations
- →The skill enforces strict size limits for `SKILL.md` and inline code blocks.
- →The skill requires specific formatting for anti-patterns.
- →The skill mandates a three-level loading system for content.
How it compares
This skill provides a meta-level framework for skill development, ensuring consistency, efficiency, and testability across all agent skills, unlike ad-hoc skill creation.
Compared to similar skills
Skill Creator side by side with the closest alternatives in the catalog.
| Skill | Installs | Updated | Safety | Difficulty |
|---|---|---|---|---|
| Skill Creator (this skill) | 0 | 5mo | No flags | Advanced |
| browser-use | 64 | 3mo | Review | Intermediate |
| prompt-optimize | 13 | 9mo | No flags | Advanced |
| ai-cost-optimizer | 9 | 5mo | Caution | Intermediate |
Try saying
Example prompts that trigger this skill in your AI assistant.
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