The agent loop
Tool call → observation → next tool call → done. The single mechanism behind every "AI agent" you've heard of.
Planning and reflection
Explicit plan-act-reflect loops. When the extra step helps, when it's just expensive theater, and how to wire it without ceremony.
Multi-agent systems
When (and when not) to add a second agent. The hype is loud; the wins are narrow.
Computer use & browser agents
Claude Computer Use, OpenAI Operator, browser-based agents. The vision-loop primitive — model takes a screenshot, emits clicks/keys, repeats.