COORDINATION MECHANICS

CHAPTER SUMMARY A handoff transfers full control from one agent to another. A subagent called as a tool keeps the main agent in charge and returns only a result. Fan-out splits independent work to run in parallel, and fan-in merges the results, with rules for missing results, inconsistent formats, and disagreements. Structured handoff objects pass only the fields the receiver needs, which is more efficient, focused, safe, and less error-prone than passing full histories. Shared state keeps durable information outside any one agent, with clear ownership, an audit trail, and a lean size. KEY TERMS REVIEW Handoff: complete transfer of control from one agent to another. Subagent as tool: an agent called like a function whose inner work is hidden. Fan-out: splitting work into independent parallel pieces. Fan-in: collecting and merging parallel results. Structured handoff object: a small, labeled package of the exact fields a receiver needs. JSON: a simple text format for labeled data. Schema: a written description of expected fields and types. Shared state: durable information stored outside any one agent. Write conflict: two writers changing the same data at once.