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Create, revise, and validate effective skills. Use when adding a new skill or changing an existing skill's SKILL.md, bundled scripts, references, assets, scaffold templates, or validation tooling.
Codex 또는 Claude로 설치 이 Prompt를 복사해 Codex, Claude 또는 다른 어시스턴트에 붙여 넣으면 Skill 페이지를 검토하고 설치를 진행할 수 있습니다.
SOC 직업 분류 기준
Use agent-browser for browser automation against real rendered web pages or web apps. Trigger when tasks require navigation, element interaction, extracting rendered data, or taking screenshots. Do not use for static fetches, direct API calls, or non-browser work.
Use when the user wants to scrape websites, crawl or map URLs, search the web, extract structured data from web pages, or run AI web agents using the Firecrawl API from the command line.
Must use any time a TypeScript file is read or written.
Must use whenever Bun is used.
OpenCode session storage locations and inspection guidance. Use when asked where OpenCode stores session data, chat history, local databases, or repo-specific session metadata.
Apply Go coding rules, design principles, and project conventions for maintainable Go code and repositories. Use when writing, reviewing, refactoring, or releasing Go code, or when working on Go-specific project structure, APIs, tests, CI, or binaries. Do not use for non-Go codebases or for language-agnostic tasks that do not depend on Go conventions.
| name | skill-writer |
| description | Create, revise, and validate effective skills. Use when adding a new skill or changing an existing skill's SKILL.md, bundled scripts, references, assets, scaffold templates, or validation tooling. |
| author | alexgorbatchev |
This skill provides guidance for creating and revising effective skills.
Skills are modular, self-contained packages that extend Claude's capabilities by providing specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific domains or tasks—they transform Claude from a general-purpose agent into a specialized agent equipped with procedural knowledge that no model can fully possess.
The context window is a public good. Skills share the context window with everything else Claude needs: system prompt, conversation history, other Skills' metadata, and the actual user request.
Default assumption: Claude is already very smart. Only add context Claude doesn't already have. Challenge each piece of information: "Does Claude really need this explanation?" and "Does this paragraph justify its token cost?"
Prefer concise examples over verbose explanations.
Treat the frontmatter description as routing metadata, not as a mini playbook. It should help the agent decide whether to load the skill, not try to enforce workflow rules before the skill body is read.
To keep skills highly efficient and avoid wasting tokens on useless meta-commentary:
SKILL.md with # Skill Name or similar. The model already knows the skill name from the metadata.## Overview or explanatory sentences like "This skill acts as a proxy..." or "Below are the guidelines...". Jump straight into the action, rules, or decision logic.description to the absolute bare minimum needed to trigger. For example, use Use when asked to commit changes in a Git repository. instead of verbose sentences detailing every scenario.Match the level of specificity to the task's fragility and variability:
High freedom (text-based instructions): Use when multiple approaches are valid, decisions depend on context, or heuristics guide the approach.
Medium freedom (pseudocode or scripts with parameters): Use when a preferred pattern exists, some variation is acceptable, or configuration affects behavior.
Low freedom (specific scripts, few parameters): Use when operations are fragile and error-prone, consistency is critical, or a specific sequence must be followed.
Think of Claude as exploring a path: a narrow bridge with cliffs needs specific guardrails (low freedom), while an open field allows many routes (high freedom).
Skills must be portable and reusable across different environments, machines, and projects.
Never include local references or hardcoded absolute paths in your skill files (SKILL.md, scripts, references, etc.).
/Users/alex/development/... or C:\Users\....scripts/my_script.ts or references/docs.md).Every skill consists of a required SKILL.md file and optional bundled resources:
skill-name/
├── SKILL.md (required)
│ ├── YAML frontmatter metadata (required)
│ │ ├── name: (required)
│ │ ├── description: (required)
│ │ └── author: alexgorbatchev (repo convention)
│ └── Markdown instructions (required)
└── Bundled Resources (optional)
├── scripts/ - Executable code (Bun/Bash/etc.)
├── references/ - Documentation intended to be loaded into context as needed
└── assets/ - Files used in output (templates, icons, fonts, etc.)
Every SKILL.md consists of:
name and description are the important triggering fields. In this repo, also include author: alexgorbatchev in skill frontmatter. Keep frontmatter minimal. In this toolchain, the validator requires name and description, permits author, and currently permits only license, allowed-tools, and metadata as additional keys beyond those. Default to name, description, and author unless you have a validated reason to add one of those supported extras.scripts/)Executable code (Bun/Bash/etc.) for tasks that require deterministic reliability or are repeatedly rewritten.
scripts/rotate_pdf.py for PDF rotation tasksreferences/)Documentation and reference material intended to be loaded as needed into context to inform Claude's process and thinking.
Rule of thumb: If you're writing detailed configuration, setup steps, or reference material that exceeds ~50 lines, put it in references/filename.md and link to it from SKILL.md. Keep SKILL.md focused on workflows and decision guidance.
references/finance.md for financial schemas, references/mnda.md for company NDA template, references/policies.md for company policies, references/api_docs.md for API specificationsreferences/setup.md - this keeps SKILL.md focused on workflows while preserving setup documentation for referenceassets/)Files not intended to be loaded into context, but rather used within the output Claude produces.
assets/logo.png for brand assets, assets/slides.pptx for PowerPoint templates, assets/frontend-template/ for HTML/React boilerplate, assets/font.ttf for typographyA skill should only contain essential files that directly support its functionality. Do NOT create extraneous documentation or auxiliary files, including:
The skill should only contain the information needed for an AI agent to do the job at hand. It should not contain auxilary context about the process that went into creating it, setup and testing procedures, user-facing documentation, etc. Creating additional documentation files just adds clutter and confusion.
Skills use a three-level loading system to manage context efficiently:
Keep SKILL.md body to the essentials and under 500 lines to minimize context bloat. Split content into separate files when approaching this limit. When splitting out content into other files, it is very important to reference them from SKILL.md and describe clearly when to read them, to ensure the reader of the skill knows they exist and when to use them.
Key principle: When a skill supports multiple variations, frameworks, or options, keep only the core workflow and selection guidance in SKILL.md. Move variant-specific details (patterns, examples, configuration) into separate reference files.
Pattern 1: High-level guide with references
# PDF Processing
## Quick start
Extract text with pdfplumber:
[code example]
## Advanced features
- **Form filling**: See [FORMS.md](FORMS.md) for complete guide
- **API reference**: See [REFERENCE.md](REFERENCE.md) for all methods
- **Examples**: See [EXAMPLES.md](EXAMPLES.md) for common patterns
Claude loads FORMS.md, REFERENCE.md, or EXAMPLES.md only when needed.
Pattern 2: Domain-specific organization
For Skills with multiple domains, organize content by domain to avoid loading irrelevant context:
bigquery-skill/
├── SKILL.md (overview and navigation)
└── reference/
├── finance.md (revenue, billing metrics)
├── sales.md (opportunities, pipeline)
├── product.md (API usage, features)
└── marketing.md (campaigns, attribution)
When a user asks about sales metrics, Claude only reads sales.md.
Similarly, for skills supporting multiple frameworks or variants, organize by variant:
cloud-deploy/
├── SKILL.md (workflow + provider selection)
└── references/
├── aws.md (AWS deployment patterns)
├── gcp.md (GCP deployment patterns)
└── azure.md (Azure deployment patterns)
When the user chooses AWS, Claude only reads aws.md.
Pattern 3: Conditional details
Show basic content, link to advanced content:
# DOCX Processing
## Creating documents
Use docx-js for new documents. See [DOCX-JS.md](DOCX-JS.md).
## Editing documents
For simple edits, modify the XML directly.
**For tracked changes**: See [REDLINING.md](REDLINING.md)
**For OOXML details**: See [OOXML.md](OOXML.md)
Claude reads REDLINING.md or OOXML.md only when the user needs those features.
Important guidelines:
Skill writing and maintenance involve these steps:
bun {{skills_dir}}/skill-writer/scripts/init_skill.ts)bun {{skills_dir}}/skill-writer/scripts/quick_validate.ts)Follow these steps in order, skipping only if there is a clear reason why they are not applicable.
Skip this step only when the skill's usage patterns are already clearly understood. It remains valuable even when working with an existing skill.
To create an effective skill, clearly understand concrete examples of how the skill will be used. This understanding can come from either direct user examples or generated examples that are validated with user feedback.
For example, when building an image-editor skill, relevant questions include:
To avoid overwhelming users, avoid asking too many questions in a single message. Start with the most important questions and follow up as needed for better effectiveness.
Conclude this step when there is a clear sense of the functionality the skill should support.
To turn concrete examples into an effective skill, analyze each example by:
Example: When building a pdf-editor skill to handle queries like "Help me rotate this PDF," the analysis shows:
scripts/rotate_pdf.py script would be helpful to store in the skillExample: When designing a frontend-webapp-builder skill for queries like "Build me a todo app" or "Build me a dashboard to track my steps," the analysis shows:
assets/hello-world/ template containing the boilerplate HTML/React project files would be helpful to store in the skillExample: When building a big-query skill to handle queries like "How many users have logged in today?" the analysis shows:
references/schema.md file documenting the table schemas would be helpful to store in the skillTo establish the skill's contents, analyze each concrete example to create a list of the reusable resources to include: scripts, references, and assets.
At this point, it is time to actually create the skill.
Skip this step only if the skill being developed already exists, and iteration or validation is needed. In this case, continue to the next step.
When creating a new skill from scratch, ALWAYS default to creating the new skill in the current project folder under .agents/skills (e.g., {proj-dir}/.agents/skills), unless the user explicitly mentions creating it in the ai-registry or globally. Always run the init_skill.ts script with Bun. The script conveniently generates a new template skill directory that automatically includes everything a skill requires, making the skill creation process much more efficient and reliable.
When maintaining init_skill.ts, scaffold template content, or validator-adjacent code, first generate a fresh skill with init_skill.ts and immediately run quick_validate.ts against that untouched scaffold before making any manual edits. Treat that init-to-validate pass as the first regression check for scaffold/validator compatibility, because it catches frontmatter and template contract drift that hand-edited examples can hide.
Usage:
# For a project-specific skill (default):
bun {{skills_dir}}/skill-writer/scripts/init_skill.ts <skill-name> --path .agents/skills
# For a global/registry skill (only if explicitly requested):
bun {{skills_dir}}/skill-writer/scripts/init_skill.ts <skill-name> --path {{skills_dir}}
The script:
scripts/, references/, and assets/After initialization, customize or remove the generated SKILL.md and example files as needed.
When editing the (newly-generated or existing) skill, remember that the skill is being created for another instance of Claude to use. Include information that would be beneficial and non-obvious to Claude. Consider what procedural knowledge, domain-specific details, or reusable assets would help another Claude instance execute these tasks more effectively.
Consult these helpful guides based on your skill's needs:
These files contain established best practices for effective skill design.
To begin implementation, start with the reusable resources identified above: scripts/, references/, and assets/ files. Note that this step may require user input. For example, when implementing a brand-guidelines skill, the user may need to provide brand assets or templates to store in assets/, or documentation to store in references/.
Added scripts must be tested by actually running them to ensure there are no bugs and that the output matches what is expected. If there are many similar scripts, only a representative sample needs to be tested to ensure confidence that they all work while balancing time to completion.
Any example files and directories not needed for the skill should be deleted. The initialization script creates example files in scripts/, references/, and assets/ to demonstrate structure, but most skills won't need all of them.
Writing Guidelines: Always use imperative/infinitive form.
Do not stop at the first draft that seems acceptable. Self-review the skill against an explicit quality bar, correct weaknesses, and repeat until the result would reasonably score 10/10 against the rubric below.
Use a bounded review loop:
Treat 10/10 as meaning the skill is clear, correctly scoped, concise, internally consistent, and ready for another agent to use without avoidable confusion. Do not chase perfection through meaningless rewrites; stop only when additional edits no longer improve correctness, clarity, triggering, or usability.
Review rubric:
description clearly say what the skill does, when to use it, and nearby cases that should not trigger it?Write the YAML frontmatter with name, description, and author:
name: The skill namedescription: This is the primary triggering mechanism for your skill, and helps Claude understand when to use it.
<base-skill>-addendum, use the description to declare the dependency because current harnesses route skills from name and description. Use this exact pattern: If <base-skill> skill is used, this skill must be used as well.docx skill: "Create, edit, and inspect .docx documents. Use when the task involves Word files, tracked changes, comments, or formatting-preserving document updates."author: Use alexgorbatchev for skills maintained in this registry.Default to name, description, and author.
If you need extra frontmatter for a specific distribution flow, verify first that the local validator accepts it. In this toolchain, the allowed extra keys beyond those are currently license, allowed-tools, and metadata.
Write instructions for using the skill and its bundled resources.
For a project-local <base-skill>-addendum, keep the body focused on the project-specific delta from the base skill. State clearly that project-specific guidance in the addendum supersedes conflicting guidance from the base skill for that project, and avoid repeating unchanged parts of the base skill.
Once development of the skill is complete, validate it. Run the validator explicitly with Bun.
These entrypoint scripts are Bun scripts. Invoke them as bun <script> ....
Quick validation:
bun {{skills_dir}}/skill-writer/scripts/quick_validate.ts <path/to/skill-folder>
If you changed scaffold generation or validator behavior, validate a freshly generated skill before validating a hand-edited one.
The script will report any validation errors and exit. Fix any validation errors and run the validation command again. The validation checks:
When changing scaffold or validator contracts, keep an end-to-end regression that covers initSkill(...) followed by validateSkill(...) so the generated default scaffold remains valid without manual cleanup.
After testing the skill, users may request improvements. Often this happens right after using the skill, with fresh context of how the skill performed.
Iteration workflow:
If the skill covers existing instructions in .github/instructions, identify any overlaps or redundancies and offer the user to update the instructions accordingly.