#Skills

A skill is a directory containing a SKILL.md file — instructions the model loads on demand instead of paying for them in every prompt. The system prompt lists each skill's name and description; the model pulls in the full body with the load_skill tool only when it decides the skill is relevant. You get a large library of specialized instructions at near-zero standing context cost.

#Writing a skill

SKILL.md is YAML frontmatter plus a Markdown body:

---
name: pdf-tools          # optional; defaults to the directory name
description: Extract and merge PDF files  # surfaced in the system prompt
tags: [docs, pdf]        # optional, string or list
---

When the user asks to merge PDFs, run ...

Drop the directory in one of the skill locations and it is picked up automatically — no code changes needed.

#Loading order

Later directories override earlier ones on name collision:

1. Global: ~/.lite-agent/skills
2. Project: <workdir>/.lite-agent/skills
3. skillsDir config option, if set

#On-demand injection

At run time only the name, description, and tags of each skill appear in the system prompt. When the model judges a skill relevant, it calls the load_skill tool with the skill name, and the full SKILL.md body is injected into context as the tool result. Skills the model never touches cost nothing beyond their one-line listing.

#Programmatic access

Use SkillLoader / loadSkillTool directly if you need the same mechanism outside createLiteAgent.

#See also

• Built-in tools — the load_skill tool reference.
• Subagents — the sibling markdown-driven capability (agents/*.md).
• Custom tools — package reusable behavior as a tool instead.
• Agent SDK overview — where skills fit in the assembled agent.