Glossary · Phase 10 · Agent harnesses
Progressive disclosure
Loading information in stages: a short summary always, details only when a task needs them.
Try it now
Prompts ask, and hooks enforce.
Learn it properly
Hooks and skills · Extend a harness at lifecycle events, and load know-how on demand. About 35 minutes.
Other terms from the same lesson
- agent skill: A folder that teaches an agent one kind of task: a SKILL.md with a name, a description and instructions, plus scripts and files.
- fail closed: When a safety check itself breaks, block the action instead of allowing it. Failing open allows it.
- lifecycle hook: Code a harness runs at a set moment, such as before or after each tool call. It can block, change or add to what happens.
Never trained an AI?
Teach a small one to write, right in your browser. It takes about 20 seconds and needs no account.