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

# Add instructions to Managed Deep Agents

> Define the system prompt for a Managed Deep Agent in instructions.md.

Instructions define the agent's behavior. They make up the core of the agent's system prompt. You can define them in a simple markdown file and they are picked up automatically by the agent.

<Note>
  Managed Deep Agents is in **public [beta](/langsmith/release-stages)** and available on [LangSmith Cloud](/langsmith/cloud) in the US region only.
</Note>

## Project structure

The `instructions.md` file lives at the project root:

```text theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}}
my-agent/
  agent.py
  instructions.md
```

## Add instructions

Create or modify `instructions.md`:

```markdown instructions.md theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}}
# Assistant

You are a helpful assistant.
```

Use this file to define the agent's role, behavior, constraints, and guidance for using its tools.

## How the agent uses instructions

Instructions are inserted into the agents system prompt on every run. They are always present and help guide the agents behavior.

## Syncing to Context Hub

When you run `mda deploy` to deploy the agent, instructions are automatically synced to the agent's [Context Hub](/langsmith/use-the-context-hub) repo. You can then edit the instructions in the LangSmith UI and have your changes automatically propagated to the agent.

## How instructions compare to other concepts

Use [skills](/langsmith/python/managed-deep-agents-skills) for task-specific procedures that the agent loads only when relevant. Use [memory](/langsmith/python/managed-deep-agents-memory) for knowledge the agent learns and retains across threads.

***

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