Subagent

A subagent is a delegated worker running in its own context window with its own system prompt and tool allowlist, returning a summary rather than its transcript. The economics are the point: it may burn tens of thousands of tokens and hand back one or two thousand. The everyday trigger is simple — reach for one when a side task would flood the main conversation with search results, logs or file contents nobody will reference again. The isolation cuts both ways: a subagent cannot see the parent conversation, so anything it needs has to be in the delegating prompt.