Skills Editor Skill
Description
This skill enables the agent to create and maintain "Agent Skills" - modular capabilities that extend the agent's functionality. It ensures that all skills follow the standardized directory structure and file format required by the deepagents environment.
When to Use
- When the user asks to "create a skill" or "add a capability".
- When the user wants to package a specific workflow (e.g., "teach the agent how to handle PDF invoices").
- When modifying existing skills to add new resources or update instructions.
Skill Structure Rules
Every skill must reside in its own directory and contain a SKILL.md file.
1. Directory Structure
Create a new directory for the skill (e.g., pdf-processing/). Inside, the SKILL.md is mandatory. Other files are optional but recommended for complex tasks to keep the context window light (Progressive Disclosure).
skill-name/
├── SKILL.md # (Required) Main instructions and metadata
├── REFERENCE.md # (Optional) Detailed API docs or reference material
├── FORMS.md # (Optional) Specialized guides
└── scripts/ # (Optional) Executable scripts
└── utility.py2. SKILL.md Format
The SKILL.md file must start with YAML frontmatter, followed by markdown instructions.
Frontmatter Requirements:
name: Max 64 chars, lowercase letters, numbers, and hyphens only. No reserved words ("anthropic", "claude").description: Max 1024 chars. Must explain what the skill does and when to use it.
Content Sections:
# [Skill Name]## Instructions: Step-by-step guidance.## Examples: Concrete usage examples.
Instructions - How to Create a Skill
MUST use the todowrite and todoread tools to track progress of the execution of the below steps:
Step 1: Check for Similar Online Skills
Before creating or editing a skill, MUST run a quick web-search (use the webfetch tool) to find any existing, similar skills online (for example, Anthropic's official skills at https://github.com/anthropics/skills/tree/main/skills or community-maintained lists). If similar skills are found:
- If the license and terms allow reuse, prefer adapting them as a template and include a clear reference/link in the new skill's SKILL.md ("Based on: ").
- If the license requires attribution or imposes conditions, include the original LICENSE.txt (or a pointer) in the new skill directory and follow the license terms. If the license is incompatible with your intended use, notify the user and request guidance before importing.
Step 2: Check for Existing Skills
Before creating a new skill and not using an online skill as a template, search for existing or similar local skills and reuse their structure, examples, and patterns as a starting point.
Step 3: Create the Directory
Create a directory under .opencode/skills/ with a kebab-case name matching the skill's purpose.
Step 4: Create SKILL.md
Write the SKILL.md file with the required frontmatter and sections.
Template:
---
name: my-new-skill
description: Brief description of what this skill does and when to use it.
---
# My New Skill
## Instructions
[Clear, step-by-step guidance for the agent to follow]
## Examples
[Concrete examples of using this skill]Step 5: Add Supporting Files (Optional)
If the skill requires large reference texts or scripts, create separate files (e.g., scripts/main.py, docs/api.md) and reference them in SKILL.md. The agent will read these only when needed.
Step 6: Update dependencies (Optional)
Add any required dependencies to the project's requirements.txt file using uv pip install <package> so the project's virtual environment is updated.
Step 7: Highlight necessary environment variables (Optional)
If a skill's scripts require environment variables (API keys, tokens, credentials), list them clearly in the SKILL.md Credentials section with the expected variable names (e.g., GITHUB_ACCESS_TOKEN, YOUTUBE_API_KEY). When creating a new skill, surface these required env vars to the user and advise adding them to the project's.env file or system environment before running the scripts.
Best Practices
- Progressive Disclosure: Don't put everything in
SKILL.md. Use it as an entry point that links to other files. - Deterministic Code: Prefer Python scripts for complex logic or data processing over natural language instructions.
- Concise Scripts: When creating script files, keep them concise—clear purpose, small functions, minimal external dependencies, and avoid unnecessary complexity.
- Clear Triggers: Ensure the
descriptionclearly states *when* the skill should be used so the router can pick it up correctly. - Confirm changes: Confirm changes with the user before executing any steps.