Skill Creator

Guidance for creating effective skills.

About Skills

Skills are modular packages that extend agent capabilities with specialized knowledge, workflows, and tools. Each skill is a directory containing a SKILL.md file and optional bundled resources.

What Skills Provide

1. Specialized workflows - Multi-step procedures for specific domains
2. Tool integrations - Instructions for working with specific file formats or APIs
3. Domain expertise - Project-specific knowledge, schemas, business logic
4. Bundled resources - Scripts, references, and assets for complex and repetitive tasks

Skill Locations in OPC

OPC uses a two-level skill system:

Level	Path	Scope
System	.opc/skills/<skill-name>/	Shared across all projects
Project	.opc/projects/<project_id>/skills/<skill-name>/	Specific to one project

Project skills with the same name override system skills. When creating new skills from project experience, always use the project level.

How Skills Are Created

Skills enter the system through two paths:

1. Agent-driven (this skill): You identify a pattern, read this guide, and create the skill manually using init_skill.py or file_write.
2. Auto-promoted: The system automatically distills playbook skills from repeated project reflections (threshold: 2 reflections with recurring patterns). These are saved as <employee>-<role>-<domain>-playbook under the project skills directory.

Both paths produce the same <skill-name>/SKILL.md format. This guide covers the agent-driven path; auto-promoted skills follow the same naming and format conventions.

Core Principles

Concise is Key

The context window is shared. Only add context the agent doesn't already have. Prefer concise examples over verbose explanations.

Anatomy of a Skill

skill-name/
├── SKILL.md (required)
│   ├── YAML frontmatter (name, description required)
│   └── Markdown instructions
└── Bundled Resources (optional)
    ├── scripts/          - Executable code
    ├── references/       - Documentation loaded as needed
    └── assets/           - Files used in output

Progressive Disclosure

1. Metadata (name + description) - Always in context (~100 words)
2. SKILL.md body - When agent reads the skill (<5k words)
3. Bundled resources - As needed (scripts can be executed without reading into context)

Naming

All skills — whether agent-created or auto-promoted — must follow these conventions:

• Lowercase letters, digits, and hyphens only (e.g., backend-api-playbook)
• Under 64 characters
• Directory name must match the name field in frontmatter

Skill Creation Process

Step 1: Understand the skill with concrete examples

Clarify use cases: what triggers this skill, what does it produce?

Step 2: Plan reusable contents

Identify what scripts, references, and assets would help.

Step 3: Initialize the skill

For project-specific skills, create under .opc/projects/<project_id>/skills/:

python3 {baseDir}/scripts/init_skill.py <skill-name> --path .opc/projects/<project_id>/skills

Options: --resources scripts,references,assets and --examples.

Step 4: Edit the skill

Write SKILL.md with:

• Frontmatter: name (hyphen-case, matches directory) and description (what it does + when to use it — this is the primary trigger for skill discovery)
• Body: Instructions, examples, references to bundled resources

Step 5: Package (optional)

python3 {baseDir}/scripts/package_skill.py <path/to/skill-folder>

Validates the skill then creates a distributable .skill zip file.

Step 6: Iterate

Test, notice struggles, improve SKILL.md and resources.