> ## Documentation Index
> Fetch the complete documentation index at: https://docs.a2v2.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Instructions

> Control how your agent behaves with instructions — its persona, tone, and rules — and manage versions.

**Instructions** are the system prompt that controls how your agent behaves —
its personality, tone, what it should and shouldn't do, and how it should handle
questions it can't answer. Knowledge tells the agent *what it knows*; instructions
tell it *how to act*.

Open **Expertise → Instructions** from the agent sidebar.

## Prerequisites

* An agent (see [Create an agent](/building/create-agent)).

## Write instructions

<Steps>
  <Step title="Open Instructions">
    In the agent sidebar, go to **Expertise → Instructions**.
  </Step>

  <Step title="Create a new instruction">
    Select **Create New Instruction**. You can start from a **role** template —
    pick a role to preview suggested default instructions — then edit to fit your
    needs.
  </Step>

  <Step title="Write the prompt">
    Describe the agent's persona, tone, scope, and rules in plain language (see
    examples below).
  </Step>

  <Step title="Save as a version">
    Saving stores the instruction as a new version (V1, V2, …). Your version
    history is preserved so you can compare and roll back.
  </Step>
</Steps>

<Frame>
  <img src="https://mintcdn.com/a2v2ai/ItYQQYTHsiiRmr-t/images/building/instructions.png?fit=max&auto=format&n=ItYQQYTHsiiRmr-t&q=85&s=84f3ef499dc3713b182e691819f1f589" alt="The Instructions editor with a role template selected and version controls." width="1440" height="900" data-path="images/building/instructions.png" />
</Frame>

<Note>
  The **Instructions** screen is available on desktop. On smaller screens you'll be
  asked to switch to a larger display.
</Note>

## Versions

Every saved change creates a new **version**. This lets you iterate safely:

| Capability                | Detail                                                         |
| ------------------------- | -------------------------------------------------------------- |
| **Version history**       | Each save is stored as V1, V2, V3, …                           |
| **Active version**        | One version is live and powers your agent's answers.           |
| **Switch active version** | Promote any version to active; your agent uses it immediately. |
| **Roll back**             | Re-activate an earlier version if a change made answers worse. |

The currently active instruction is shown on the [Sandbox](/testing/sandbox) under
**Instructions**, with a shortcut to **Manage instructions**.

<Tip>
  Use the **Improve the instruction** helper to refine wording, then save it as a
  new version so you can always compare against the previous one.
</Tip>

## What to put in instructions

<AccordionGroup>
  <Accordion title="Persona & tone">
    "You are a friendly support assistant for Acme. Be concise and warm. Use
    plain language and avoid jargon."
  </Accordion>

  <Accordion title="Scope & boundaries">
    "Only answer questions about Acme products. If asked about anything else,
    politely say it's outside your scope."
  </Accordion>

  <Accordion title="Fallback behavior">
    "If you can't find the answer in the knowledge base, say so and offer to
    connect the user with the team at [support@acme.com](mailto:support@acme.com) — don't guess."
  </Accordion>

  <Accordion title="Formatting">
    "Use short paragraphs and bullet points. Include links when they're in the
    source material."
  </Accordion>
</AccordionGroup>

## Tips

<Tip>
  * Be explicit about **what not to do** — telling the agent not to guess is one of
    the highest-impact rules you can add.
  * Change **one thing at a time** and save a new version, so you can tell what
    improved answers.
  * Test every change in the [Sandbox](/testing/sandbox) or compare versions in the
    [Playground](/testing/playground) before going live.
</Tip>

## Related

<CardGroup cols={2}>
  <Card title="Choose a model" icon="microchip" href="/building/model-settings" />

  <Card title="Test in the Sandbox" icon="vial" href="/testing/sandbox" />

  <Card title="Compare in the Playground" icon="code-compare" href="/testing/playground" />

  <Card title="Add knowledge" icon="database" href="/knowledge-base/overview" />
</CardGroup>