Skill System

The cosh-core skill system allows defining reusable Agent skills via Markdown files. LLM can proactively discover and invoke registered skills during conversations.

Skill Search Paths

Skills are searched in the following directories by priority (highest to lowest):

Level	Path	Description
Project	<project>/.copilot-shell/skills/	Project-level skills
Custom	config.toml skills.custom_paths	Custom paths
User	~/.copilot-shell/skills/	User-level skills
Extension	Extension skill_dirs declaration	Registered via extensions
System	/usr/share/anolisa/skills/	System-level (RPM installed)

Skills with the same name are overridden by priority (Project > Custom > User > Extension > System).

Skill File Format

A skill is a Markdown file (.md) containing YAML frontmatter and body:

---
name: check-disk
description: Check disk usage and provide recommendations
---

# Check Disk Usage

1. Run `df -h` to get mount point utilization
2. Issue warnings for partitions with usage above 80%
3. Run `du -sh /var/log` to check log directory size

Configuration

[skills]
custom_paths = ["~/my-skills", "/opt/team-skills"]

Runtime Behavior

1. On startup, SkillManager scans all paths and builds a skill cache
2. The skill list is injected into the system prompt's # Available Skills section
3. LLM invokes skills via the skill tool (passing the skill name)
4. Skill content is injected into the conversation context as a system message
5. File system watcher automatically detects new/modified skill files (hot reload)

Disabling Skills

Managed via the state file ~/.copilot-shell/states/skills.json:

{ "disabled": ["dangerous-skill"] }

Disabled skills do not appear in the LLM's visible list.

Difference from copilot-shell

The cosh-core skill system mirrors copilot-shell's skill discovery logic but is implemented in pure Rust. The same skill files can be loaded by both simultaneously.