Multi-Agent and Protocol Terms: Orchestration, Hierarchical Agents, Router, MCP, A2A
~12 min read
The 7 terms covering how multiple agents (and the tools/other agents they connect to) are coordinated — from orchestration and hierarchy to the MCP and A2A protocols.
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Key points
- •Orchestration is the activity of coordinating multiple agents; a Multi-agent system is the resulting team being orchestrated
- •Hierarchical Agents: a supervisor delegates to sub-agents, rather than all agents coordinating as equals
- •Router: the mechanism that decides which agent or tool should handle a given task
- •Human-in-the-loop: a checkpoint where humans intervene in or guide an agent's (or multi-agent system's) decisions
- •MCP standardizes agent-to-tool connections; A2A standardizes agent-to-agent connections — both avoid custom wiring per pairing