ModelRefs / Multi-Agent System — AI Glossary

Multi-Agent System — AI Glossary

An architecture where multiple specialized AI agents collaborate, delegate tasks, and exchange information to complete goals too complex for a single agent.

Overview

Multi-agent systems decompose complex tasks across specialized agents: a planner routes sub-tasks to a researcher, coder, and critic agent. Patterns: orchestrator-workers, peer-to-peer, hierarchical. Challenges: inter-agent communication, error propagation, and cost accumulation.

Reference details

Topicagents
Also known asmulti-agent, multi-agent orchestration, multi-agent-system
Last reviewed2026-06-24

Example: Where the errors go

A planner, a researcher and a critic each at 90% reliability do not give you 90% end to end. Errors compound along the chain: 0.9 × 0.9 × 0.9 ≈ 0.73. Add a step and it falls again. Multi-agent designs buy specialisation and pay for it in compounding failure and multiplied token cost.

1 agent  @ 0.90            = 0.90
3 agents @ 0.90 in series = 0.90^3 = 0.729
5 agents @ 0.90 in series = 0.90^5 = 0.590

Commonly confused with

Multiple prompts is not multiple agents. Calling a model three times with different instructions is a pipeline. A multi-agent system has agents that decide, delegate and react to each other's output — which is also what makes it hard to debug.

When to use it

Reach for it when:

  • Sub-tasks genuinely need different tools, context or permissions
  • One agent's context window cannot hold the whole problem
  • A separate critic or verifier measurably improves output quality

Reach for something else when:

  • A single agent with good tools would do — this is the common over-build
  • You cannot trace which agent caused a bad outcome
  • Cost matters: every agent adds a full model call, and they multiply

Referenced by

This term is used by the following ModelRefs references:

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Frequently asked questions

What is Multi-Agent System?

An architecture where multiple specialized AI agents collaborate, delegate tasks, and exchange information to complete goals too complex for a single agent.

Is Multi-Agent System the same as multi-agent?

Yes — multi-agent, multi-agent orchestration, multi-agent-system are common aliases for Multi-Agent System.

What concepts are related to Multi-Agent System?

Closely related concepts include agent, handoff, agentic loop, orchestrator agent.