Agent Systems: Inter-Agent Communication and Protocols

Problem

Agents have different context, assumptions, tools, and lifetimes. An implicit shared conversation does not provide a reliable coordination contract.

Message contract

sender · recipient · task id · artifact · provenance · status · requested action

Mathematical messages should carry hypotheses, dependencies, uncertainty, and unresolved obligations, not only conclusions. Version or identify artifacts so that a later message cannot silently refer to changed content.

Protocol versus orchestration

Orchestration decides who acts next and when the task ends. A protocol specifies what is transferred between components. Tool protocols such as MCP and agent- to-agent protocols are useful because they make the seam explicit.

Forces and failure modes

Protocols support independent deployment and replacement, but add serialization, schema evolution, and failure handling. Guard against inconsistent state, duplicated work, unbounded message histories, and messages that omit assumptions.

Design test

Could a new agent reconstruct the claim, its assumptions, evidence, and next action from the message alone?

Figure

Figure: independent agents coordinate through explicit task, evidence, status, and error messages.