Your Agents Are Fine. The Handoff Between Them Isn't.

Most multi-agent demos show you a single agent wearing a costume. They show Agent A doing a task and then Agent B doing another. They do not show what happens when Agent A fails to give Agent B what it needs.

I shipped three multi-agent systems in production this year. The agents were not the hard part. The handoffs were.

A handoff is more than passing text. You must manage:

  • Schema alignment: Agent B must parse Agent A output every time.
  • Failure propagation: The system must know when one agent fails.
  • Context hygiene: Every handoff adds noise to your window.

The biggest mistake is treating agents like black boxes connected by a string. You prompt Agent A, get a result, and shove it into Agent B. This works until it breaks. When it breaks, you will not know why.

Avoid these three common failure modes:

  1. Silent truncation: Agent A produces too much data. Agent B cuts the end off. Agent B then processes partial data and gives you nonsense. Measure your token counts at every step.

  2. Schema drift: You change a prompt for Agent A. Now it returns a different format. Agent B breaks because it expects the old format. Use structured output like Pydantic instead of relying on prompts.

  3. Race conditions: You run five workers at once. Three finish, but two are still running. Your aggregator starts early with partial data. This works in tests but fails in production. Use a barrier to wait for all tasks.

My first system was clever but messy. It used dynamic routing and implicit handoffs. It worked until it hit real traffic and failed silently.

My second system was ugly but correct. Every handoff used a typed contract. Every failure was explicit. Every agent was isolated.

My current system combines both. It uses the discipline of the second version but hides the boring code behind a framework.

If you build multi-agent systems, start with the ugly and correct version. Do not try to be clever first. Get it right in production, then make it elegant.

The handoff problem does not get easier. But you stop being surprised by it.

Source: https://dev.to/mrclaw207/your-agents-are-fine-the-handoff-between-them-isnt-2dij

Optional learning community: https://t.me/GyaanSetuAi