skill-builder
Creates, refines, and validates Agent Skills following the open standard at agentskills.io, Claude Code extensions, and Anthropic best practices. Use when building, creating, generating, or designing new skills.
- Installs
- 226
- Last 24h
- —
- Trending rank
- —
- Security
- Not audited
Install
Works with every agent the skills CLI supports.
npx skills add https://github.com/rysweet/amplihack --skill skill-builder- 01
Install
Run the command in your project. The CLI asks which agents to install for.
- 02
Describe the task
Ask your agent for something this skill covers. It loads skill-builder automatically when relevant.
- 03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.
SKILL.md
The instructions your agent reads when the skill is triggered.
Skill Builder
Purpose
Creates production-ready Agent Skills following the official specifications and best practices.
When I Activate
I automatically load when you mention:
- "build a skill" or "create a skill"
- "generate a skill" or "make a skill"
- "design a skill" or "new skill"
Authoritative References (Read These First)
Before creating any skill, read the current versions of these docs:
- Agent Skills Specification (the open standard): https://agentskills.io/specification
- Skill Authoring Best Practices (Anthropic): https://platform.claude.com/docs/en/agents-and-tools/agent-skills/best-practices
- Claude Code Skills Documentation (Claude Code extensions): https://docs.claude.com/en/docs/claude-code/skills
- Example Skills (reference implementations): https://github.com/anthropics/skills
These are the source of truth. If anything in this skill contradicts those docs, the official docs win.
What I Do
Create skills in 5 steps:
- Clarify → Define purpose, scope, activation keywords
- Design → Plan structure, decide on progressive disclosure
- Generate → Create SKILL.md with proper frontmatter and body
- Validate → Check against spec and best practices
- Test → Verify activation and behavior
Frontmatter (Agent Skills Spec)
Only two fields are required:
---
name: my-skill
description: What this skill does and when to use it. Include specific keywords for discovery.
---
Optional fields: license, compatibility, metadata, allowed-tools.
Claude Code adds: disable-model-invocation, user-invocable, model,
context, agent, hooks, argument-hint.
Do NOT use: version (use metadata.version), auto_activates,
priority_score, source_urls, evaluation_criteria, invokes,
philosophy, maturity — none of these are recognized by any runtime.
Key Best Practices
From the official best practices:
Conciseness
- Claude is already smart. Only add context it doesn't have.
- Challenge every paragraph: "Does this justify its token cost?"
- SKILL.md body under 500 lines.
Description Quality
- Write in third person ("Processes Excel files", not "I help you")
- Include both what the skill does AND when to use it
- Include specific trigger keywords for discovery
- Max 1024 characters
Progressive Disclosure
- Metadata loaded at startup (name + description only)
- SKILL.md loaded when skill activates
- Supporting files loaded only when needed
- Keep references one level deep from SKILL.md
Degrees of Freedom
- High freedom: Multiple valid approaches, context-dependent
- Medium freedom: Preferred pattern exists, some variation OK
- Low freedom: Fragile operations, exact sequence required
No Time-Sensitive Content
- Never write "as of today", "recently added", "new in v3.0"
- Use an "old patterns" section for historical context if needed
Feedback Loops
- Run validator → fix errors → repeat
- Include verification steps for critical operations
Validation Checklist
✅ Frontmatter: name and description present and valid
✅ Name: Lowercase, hyphens only, 1-64 chars, matches directory name
✅ Description: 1-1024 chars, third person, includes trigger keywords
✅ Body: Under 500 lines
✅ References: One level deep from SKILL.md
✅ No stale content: No temporal references
✅ Consistent terminology: One term per concept throughout
✅ Tested: Works with at least 3 representative prompts
Supporting Files
- reference.md: Detailed patterns, architecture, validation rules
- examples.md: Skill creation workflows and examples
FAQ
What does the skill-builder skill do?
Creates, refines, and validates Agent Skills following the open standard at agentskills.io, Claude Code extensions, and Anthropic best practices. Use when building, creating, generating, or designing new skills.
How do I install skill-builder?
Run npx skills add https://github.com/rysweet/amplihack --skill skill-builder in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/skill-builder/ (personal) or .claude/skills/skill-builder/ (project).
Which AI agents can use skill-builder?
Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.
Is skill-builder safe to install?
No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.
Who maintains skill-builder?
It is published by rysweet in rysweet/amplihack. It has 226 recorded installs.
More from rysweet/amplihack
cybersecurity-analyst
rysweet/amplihack
Analyzes events through cybersecurity lens using threat modeling, attack surface analysis, defense-in-depth, zero-trust architecture, and risk-based frameworks (CIA triad, STRIDE, MITRE ATT&CK). Provides insights on vulnerabilities, attack vectors, defense strategies, incident response, and security posture. Use when: Security incidents, vulnerability assessments, threat analysis, security architecture, compliance. Evaluates: Confidentiality, integrity, availability, threat actors, attack patterns, controls, residual risk.
lawyer-analyst
rysweet/amplihack
Analyzes events through legal lens using statutory interpretation, case law analysis, legal reasoning, constitutional principles, and multiple legal frameworks (common law, civil law, international law). Provides insights on legal rights, obligations, liabilities, remedies, and compliance requirements. Use when: Legal disputes, contracts, regulations, compliance, rights analysis, liability assessment. Evaluates: Legal obligations, rights, liabilities, remedies, precedent, statutory authority, constitutionality.
psychologist-analyst
rysweet/amplihack
Analyzes events through psychological lens using cognitive psychology, social psychology, developmental psychology, clinical psychology, and neuroscience. Provides insights on behavior, cognition, emotion, motivation, group dynamics, decision-making biases, mental health, and individual differences. Use when: Behavioral patterns, decision-making, group behavior, mental health, leadership, persuasion, trauma, development. Evaluates: Cognitive processes, emotional responses, motivations, biases, group dynamics, personality, mental states.
mermaid-diagram-generator
rysweet/amplihack
Converts architecture descriptions, module specs, or workflow docs into Mermaid diagrams. Use when visualizing brick module relationships, workflows (DDD, investigation), or system architecture. Supports: flowcharts, sequence diagrams, class diagrams, state machines, entity relationship diagrams, and Gantt charts. Generates valid Mermaid syntax for embedding in markdown docs.
pptx
rysweet/amplihack
Presentation creation, editing, and analysis. When Claude needs to work with presentations (.pptx files) for: (1) Creating new presentations, (2) Modifying or editing content, (3) Working with layouts, (4) Adding comments or speaker notes, or any other presentation tasks
economist-analyst
rysweet/amplihack
Analyzes events through economic lens using supply/demand, incentive structures, market dynamics, and multiple schools of economic thought (Classical, Keynesian, Austrian, Behavioral). Provides insights on market impacts, resource allocation, policy implications, and distributional effects. Use when: Economic events, policy changes, market shifts, financial crises, regulatory decisions. Evaluates: Incentives, efficiency, opportunity costs, market failures, systemic risks.
Popular ai & agents skills
google-agents-cli-publish
google/agents-cli
This skill should be used when the user wants to "publish an agent", "publish my ADK agent", "register an agent with Gemini", "publish to Gemini" (formerly Gemini Enterprise), or needs guidance on the agents-cli publish gemini command. Also use when the user wants to "manage agents in Agent Registry", "list/update/delete registered agents", or "register an MCP server". Covers ADK vs A2A registration modes, programmatic and interactive usage, flag reference, auto-detection from deployment metadata, Agent Registry fleet management, and troubleshooting. Part of the agents-cli skills suite. Do NOT use for deployment (use google-agents-cli-deploy).
google-agents-cli-eval
google/agents-cli
This skill should be used when the user wants to "run an evaluation", "evaluate my agent", "evaluate my ADK agent", "write an eval dataset", "analyze eval failures", "compare eval results", "optimize agent", or needs guidance on the Gemini platform eval methodology and the Quality Flywheel. Covers eval metrics, dataset schema, LLM-as-judge scoring, and common failure causes. Applies to any agents-cli project, whatever framework the agent is written in. Do NOT use for agent API code patterns (ADK: use google-agents-cli-adk-code), deployment (use google-agents-cli-deploy), or project scaffolding (use google-agents-cli-scaffold).
skill-creator
anthropics/skills
Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an existing skill, run evals to test a skill, benchmark skill performance with variance analysis, or optimize a skill's description for better triggering accuracy.
codex-pet
prime-skills/runcomfy-agent-skills
Codex Pet generator on RunComfy. Build a Codex-compatible Codex Pet spritesheet.webp + pet.json from a single reference image, drop it into ${CODEXHOME:-$HOME/.codex}/pets/ / and Codex picks it up as a custom Codex Pet next to the 8 built-ins. This skill produces the exact Codex Pet atlas Codex expects (1536x1872 PNG/WebP, 8 cols x 9 rows, 192x208 cells, 9 animation states — idle, running-right, running-left, waving, jumping, failed, waiting, running, review). Calls OpenAI GPT Image 2 edit ONCE via the local RunComfy CLI as runcomfy run openai/gpt-image-2/edit to produce a canonical Codex Pet pose, then assembles all 9 animation rows programmatically with ImageMagick micro-transforms — no Codex Pro, no $imagegen, no OPENAIAPIKEY required, only RUNCOMFYTOKEN. Triggers on "codex pet", "create codex pet", "make codex pet", "hatch codex pet", "/hatch image", "desktop pet codex", "codex pets", "spritesheet.webp", or any explicit ask to build a custom pet for OpenAI Codex.
full-output-enforcement
leonxlnx/taste-skill
Overrides default LLM truncation behavior. Enforces complete code generation, bans placeholder patterns, and handles token-limit splits cleanly. Apply to any task requiring exhaustive, unabridged output.
executing-plans
obra/superpowers
Use when executing an implementation plan in the current session as the implementer yourself — your human partner chose inline execution, or no subagent tool is available