# System prompt builder

> Define a role, boundaries and expected output.

[Open tool](https://www.toolcabana.com/lb/system-prompt) · [AI and prompt tools](https://www.toolcabana.com/lb/category/ai-and-prompt-tools)

Tool ID: system-prompt. Requested language: lb. Description language: en. Complete guide translation: no; untranslated sections use English.

## Overview (en)

System prompt builder assembles a reusable instruction block that defines an assistant's role, audience, tone, boundaries and expected output. Enter the assistant's main job as the task, adjust the five fields, and get plain text with each part under its own heading plus a closing quality check that asks for stated assumptions and uncertainty.

## Supported tasks (en)

Define a role, boundaries and expected output.

## Steps (en)

1. Paste the source into the input editor, or load the built-in example.
2. Adjust the basic settings, then open Advanced mode for export and fine-tuning options. Custom settings stay active when the panel is closed.
3. Run system prompt builder, review the output, then use the available copy or download controls.

## Settings

- Role / expertise (en; key: role; type: text)
- Audience (en; key: audience; type: text)
- Tone (en; key: tone; type: text)
- Constraints (en; key: constraints; type: textarea)
- Output format (en; key: format; type: text)

## Limitations (en)

Text operations generally accept up to 2,000,000 characters. Individual parsers, generators and formulas apply additional limits shown by their controls.

## Example input

```text
Explain a complex topic using a concrete example and three practical steps.
```

## Privacy and connections (en)

This operation processes its source in your browser. Copy and download are explicit actions; source input is not saved in an account or history.

## Questions (en)

### How do I set boundaries in a system prompt?

Put rules in the Constraints field, one per line if you like, such as topics to decline or sources to rely on. The text is placed verbatim under a Constraints heading, so write it as direct instructions addressed to the assistant.

### What sections does the generated system prompt contain?

Role, Task, Audience, Tone, Constraints, Output format and Quality check, in that order. Your main input fills Task, the five settings fill their matching sections, and the Quality check wording is fixed by the template.

### Can I save the system prompt as a file?

Yes. Besides copying, you can download the result as system-prompt.txt, a plain text file containing exactly the generated sections. That makes it easy to paste into an assistant's custom instructions or keep alongside your project files.

### Where is my input processed?

This operation processes its source in your browser. Copy and download are explicit actions; source input is not saved in an account or history.

### What are the input limits?

Text operations generally accept up to 2,000,000 characters. Individual parsers, generators and formulas apply additional limits shown by their controls.

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