Lately, I've been hearing a lot about multi-agent AI systems. As someone who is always thinking about not just using these services but building them myself, I've been keen to know how to construct high-performance AI agents. Last week, Anthropic published an article titled, "How we built our multi-agent research system(1)," which describes their construction method in detail. So today, using this article as a reference, I'd like to explore the best practices for creating multi-agent AI systems with all of you. Let's get started!

1. Why do we need so many agents?

ChatGPT, which debuted at the end of November 2022, was a single model. Since then, several services using generative AI have appeared, but initially, most of them used a single AI. So why have we recently seen a rise in methods that connect multiple generative AIs to operate as a single system? I believe it's because it has become clear that there are limits to what a single generative AI can accomplish when faced with complex tasks. It has gradually become apparent that by connecting and integrating several agents, even complex tasks can be handled. This trend has become particularly noticeable in conjunction with the performance improvements of standalone generative AI models like Gemini 1.5 Pro and OpenAI's o3.

2. What kind of agent structure should we build?

The Anthropic article included a wonderful chart that I'd love to reference. The key lies with the "Lead agent" and the "sub-agents" placed beneath it.

Here is Anthropic's explanation: "The multi-agent architecture in action: user queries flow through a lead agent that creates specialized subagents to search for different aspects in parallel" . While the chart shows three sub-agents, it's a matter of course that more may be needed to handle more complex tasks.

3. How do you coordinate many agents?

I've described the move to multi-agent AI as if it's all upside, but it requires numerous AI agents to function as expected. Getting a desired response from a single generative AI can be quite a challenge, so is it even possible to control multiple, simultaneously operating AI agents to meet our expectations? The key seems to lie in the "prompt." In fact, the Anthropic article contains countless, very helpful methods for prompt creation. Here, I'd like to introduce two representative examples. For the rest, I highly recommend reading the original article for yourself.

"Teach the orchestrator how to delegate. In our system, the lead agent decomposes queries into subtasks and describes them to subagents. Each subagent needs an objective, an output format, guidance on the tools and sources to use, and clear task boundaries. Without detailed task descriptions, agents duplicate work, leave gaps, or fail to find necessary information.

"Guide the thinking process. Extended thinking mode, which leads Claude to output additional tokens in a visible thinking process, can serve as a controllable scratchpad. The lead agent uses thinking to plan its approach, assessing which tools fit the task, determining query complexity and subagent count, and defining each subagent’s role.

In a nutshell, I think it comes down to "describing things meticulously." Apparently, simple and short instructions like "Research the semiconductor shortage" did not work well, so it seems necessary to write prompts for multi-agent AI as meticulously as possible. I'm going to work on writing better prompts from now on.

What did you think? It appears that various techniques are necessary to make multi-agent AI systems operate as intended. As the performance of generative AI improves in the future, the required orchestration techniques will also change. I want to continue to stay updated and incorporate the latest cutting-edge technologies. That's all for today. Stay tuned!

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1) , "How we built our multi-agent research system”, Anthropic, June 13, 2025

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