Glossary
Orchestration
The rules for which step, tool, or agent runs next, and who owns the answer.
Orchestration is the part of a harness that chooses the next step and passes the result along. In a single agent, that can be the loop that calls a tool and continues. In a multi-agent setup, it also decides who owns the reply.
OpenAI’s Agents SDK describes two patterns. A handoff gives the next specialist ownership of that branch. An agent used as a tool leaves the manager in charge of the final answer. Google’s ADK 2.0 page describes another form: a graph of agents, tools, and functions with explicit routes. LangChain’s March 10, 2026 anatomy post lists orchestration as subagent spawning, handoffs, and model routing.
The longer guide is What is an AI agent harness?.