You can build one agent in an afternoon. Add a second, and suddenly you have a distributed system with opinions.

Context engineering is difficult enough for one agent. Across many, it becomes a coordination problem: What does each agent know? What should it remember? What gets lost along the way? Most systems answer with prompts and tool calls, shoveling state through text and hoping the important bits survive. This works surprisingly well until the system becomes slow, expensive, or confidently wrong in ways that are miserable to debug.

We will trace how information moves through modern multiagent systems using memory, skills, hooks, subagents, MCP, and A2A. You will learn what each layer contributes, how to compose them, and where the tradeoffs hide.

Finally, we will look beyond today’s text passing architectures and ask: If agents stop trading text, what should they share instead?