What is a Skill
A Skill is an on-demand instruction unit loaded by an agent. It contains operational instructions, reference documentation, and execution scripts. Rather than relying on a single monolithic system prompt stuffed with everything, an agent retrieves relevant Skills at inference time — loading only what the current task actually needs.
Agent Skills Open Standard
Skills follow the Agent Skills Open Standard — a shared format designed to work across tools. A Skill is a directory with SKILL.md as its entry point, plus optional supporting files:
my-skill/
├── SKILL.md # Entry point — yaml frontmatter + markdown instructions
├── references/ # Domain docs, API specs — loaded on demand
│ └── api-docs.md
├── scripts/ # Scripts the agent can execute
│ └── helper.py
├── examples/ # Examples showing expected output format
│ └── sample.md
└── templates/ # Templates for the agent to fill in
└── template.mdSkills on Vtrix natively support this standard, and are equally compatible with Claude Code, Cursor, Windsurf, and any other tool that follows the spec.
Tips
- Write a clear description: The description is what the agent sees in its tool list. A vague “docs” is useless — “API documentation for the payment service, including endpoint list, authentication method, and error codes” gives the agent what it needs to decide when to load the Skill
- Keep Skills focused: One Skill, one topic. Instead of one giant Skill, split into independent units like
code-review,security-checklist, andapi-reference— the agent loads only what it needs at the moment - Use supporting files for heavy content: Put large reference docs, API specs, and detailed examples under
references/orexamples/. Keep the main instructions concise and reference those files when detail is needed - Use relative paths between files: Reference supporting files with relative paths like
[See reference](references/api-docs.md). The agent can load them on demand viaskill_get, and local agents can access them directly via the filesystem