skill-editor

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.py

2. 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 description clearly 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.