Subagent
Also: subagents, multi-agent
A helper agent that a main agent hands part of a job to.
The fuller definition
A subagent is a separately invoked agent assigned a bounded task by another agent or coordinating system. It may have its own context and tools.
- ObserveRead the task, the current state, and the last result.
- DecidePropose the next action: a search, a file read, a calculation.
- ActThe harness runs the action, if permitted.
- CheckStop condition met? If not, loop again.
The model proposes; the surrounding software executes and records. Where the loop may act, and when it must stop and ask, are decisions made outside the model.
A concrete example
One worker extracts dates while another checks the cited passages, with explicit input and output boundaries.
The distinction that matters
Two subagents can share the same mistaken premise; agreement is not independent proof.
Related terms
Orchestration
Managing the steps in a workflow. It sets which step runs next and how results pass between tools.
Agents & automationAI agent
An AI system that takes steps to do a task. It may choose tools, search, or work with files. Its access should have clear limits.
Reliability & securityEvaluation (eval)
Testing an AI tool on a set of tasks to see how well it actually does.
Where it is taught
Prompts, skills, workflows, and agentsSource and further reading
Anthropic · Building effective agentsThe definition and example are written for this library. The link gives background, official documentation or legal authority as labelled. Legal scope depends on the jurisdiction and current text; product features depend on release and settings.