> ## Documentation Index
> Fetch the complete documentation index at: https://docs.circuit.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Constraining output

> How to control and constrain the format, length, and content of agent responses.

You can control how an agent responds by giving it explicit constraints. This is useful when you need shorter answers, a specific format, or want the agent to keep its working process out of sight.

## Example: concise responses for an embedded chat widget

Suppose you have an agent embedded as a chat widget on your website. You want it to answer questions briefly and without showing a visible chain of searching and reasoning. You can instruct the agent:

> Make sure you respond concisely in 100 words or less, and that any searching or other deliberation you do happens in a Task.

This tells the agent two things: keep responses short, and do its background work (searching indexes, reading documents) inside a task so the user only sees the final answer.

## How to apply constraints

There are two ways to give an agent constraints like this:

<Tabs>
  <Tab title="Per-conversation">
    Type the constraint directly into the chat before your question. For example:

    > Respond in 100 words or less. What are the installation requirements for the X500?

    This applies only to the current conversation. It's useful for one-off situations where you need a different response style.
  </Tab>

  <Tab title="Permanent (agent instruction)">
    Update the agent's instruction so the constraint applies to every conversation. You can do this in two ways:

    * **Through the admin UI**: edit the agent's instruction in the [agent configuration](/admin/agent-configuration#agent-instructions) page.
    * **By asking the agent**: tell the agent directly to update its own instruction. For example: "Update your instruction to always respond in 100 words or less."

    <Note>
      Updating agent instructions requires admin permissions. If you don't have admin access, use the per-conversation approach or ask your administrator to make the change.
    </Note>
  </Tab>
</Tabs>