Creating Skills
Skills are reusable instructions that sandbox agents can load when a task matches the skill's purpose. They are not API tools and they do not grant new network access by themselves. Use them for repeatable procedures, repo-specific operating knowledge, QA playbooks, investigation steps, or formatting rules.
Put organization skills in an overlay repo under .agents/skills/. See
Using an overlay for packaging, mount paths, and chart
configuration.
Skills are loaded from the sandbox overlay. In an overlay deployment, they must
exist under /home/agent/overlay/org/.agents/skills in the sandbox container.
The sandbox entrypoint copies those skills into the agent workspace during
startup.
Write SKILL.md
Keep the entrypoint concise and action-oriented:
# Incident Response
Use this skill when investigating a production incident, failed rollout, or
service outage.
## Workflow
1. Identify the affected service, namespace, and timeframe.
2. Check rollout history and current pod health.
3. Inspect logs around the first failure.
4. State root cause, blast radius, and recovery path.Add references only when they save context. Put long runbooks in
references/, scripts in scripts/, and examples in examples/.
What belongs in a skill
Good skills:
- encode a repeated workflow
- say when they should be used
- point at local scripts or references
- keep the first page short
- avoid secrets and credentials
Avoid using skills for tool credentials, API clients, or durable automation. Those belong in tools, secret configuration, and workflows.
Verify
Start an agent with the overlay loaded and ask it to inspect available skills. For a running sandbox, the agent can confirm overlay state with:
echo "$CENTAUR_OVERLAY_DIR"
ls "$CENTAUR_OVERLAY_DIR/.agents/skills"If a skill is missing, check the overlay image contents and that the directory
contains SKILL.md.