Multi-agent crews: two roles and a brief that can say no

A crew helps when a second role can reject a sentence. Handoffs, empty-brief stops, and a cut list.

Sandeep Jaiswal·1 July 2025 · 5 min read

One agent with one job is hard enough. A “crew” is several agents that hand work to each other — researcher, writer, reviewer — as if they were people. This post teaches when that helps, when it is theatre, and how to run a two-person crew you can actually check.

The problem a crew is for

Some jobs have a natural split.

One role should only look things up.
One role should only write.
One role should only reject a sentence that is not supported.

If those three jobs share one prompt, the same voice will research, draft, and then politely agree with itself. A crew makes the disagreement real: the reviewer cannot see the writer’s pep-talk. It sees the draft and the sources.

A crew is useful when a second role can say no. If nobody can say no, you made a chorus.

What is not a crew

Three prompts that run in a line and always say “looks good” are not a crew. That is a pipeline with extra names.

A crew is also not “ten agents for a to-do list.” If one function can do the job, use one function.

Use a crew when:

The jobs need different tools (search vs write vs a linter).
You want a reject that the writer does not control.
You can name the handoff: what exactly gets passed.

Skip a crew when the job is one retrieve-and-answer. That is RAG, maybe with a check node. You do not need characters.

Two roles, one handoff

Start with two, not five.

Researcher. Tools: search a folder or the web you allow. Output: a brief of facts, each with a source. No prose essay.

Writer. No search tool. Input: the user job plus the brief. Output: a short draft that may only use those facts.

The handoff is the brief, not a chat. If the writer can also search, it will skip the brief and you are back to one agent.

Done looks like this:

Case	What should happen
The folder has three facts	Brief has three sourced lines. Draft uses only those
The folder is empty	Researcher returns empty. Writer does not invent. It stops
Writer adds a fourth “fact”	A third role — or you, by eye — throws that sentence out

A reviewer role is optional on day one. Your eye is the reviewer until the handoff is clean.

How the handoff should look

Write the brief as a list, not a paragraph.

- Fact: attendance rule is 75%. Source: notes.md / Attendance
- Fact: 36 of 40 is safe. Source: notes.md / Examples

The writer’s prompt says: use only this list. If you need another fact, stop.

That is the same idea as a schema in a single agent. The crew just puts the schema on the table between two roles.

The brief is the product of the first role. The draft is not allowed to go around it.

Adding a reviewer without theatre

A reviewer needs a job that can fail.

Good: “Delete any sentence that is not grounded in the brief. Return the surviving sentences and the ones you cut.”

Bad: “Make it better and more professional.” That never fails, so it never teaches you.

Give the reviewer the brief and the draft. Do not give it the researcher’s chain of thought. If it can see the writer’s excuses, it will forgive them.

Cap the loop. Writer → reviewer → writer once. Then stop and show the cuts. A crew that debates forever is a bill.

A useful reviewer produces a cut list. A useless one produces praise.

Common mistakes

Casting a play. “CEO agent, intern agent, critic agent” on a 200-word task. Two roles. Named handoff.

Shared memory that is a novel. Each role should see only what it needs. The reviewer does not need the search trace. The writer does not need the reviewer’s inner monologue.

Tools on every role. If everyone can search, everyone will.

No empty-brief stop. Then the writer fills the silence with general knowledge and you call it teamwork.

Measuring success by length. A shorter draft with one cut is a better crew than three pages of agreement.

Practise

Write the brief format on paper.
Run researcher only. Empty folder must return empty.
Hand the brief to a writer with no search tool.
Plant a fourth fact in the draft yourself. See if you (or a reviewer) catch it.
Only then add a reviewer with a cut list and a one-retry cap.

You can do this with CrewAI, with LangGraph nodes named by role, or with three functions. The brand of the crew is optional. The handoff is not.

Checklist

You can say why a second role exists in one sentence.
The handoff is a brief, not a chat dump.
The writer cannot search.
Empty research stops the writer.
A reviewer, if you have one, can cut, not only praise.
You have a planted-lie case.

The next step is two roles and a brief you can read, not a larger cast.