# Describe Tool

The `describe` tool scans the PR code changes, and automatically generates PR description - title, type, summary, code walkthrough and labels.
It can be invoked manually by commenting on any PR:
```
/describe
```
For example:

<kbd><img src=./../pics/describe_comment.png width="768"></kbd>

<kbd><img src=./../pics/describe.png width="768"></kbd>

The `describe` tool can also be triggered automatically every time a new PR is opened. See examples for automatic triggers for [GitHub App](https://github.com/Codium-ai/pr-agent/blob/main/Usage.md#github-app-automatic-tools) and [GitHub Action](https://github.com/Codium-ai/pr-agent/blob/main/Usage.md#working-with-github-action)

### Configuration options

Under the section 'pr_description', the [configuration file](./../pr_agent/settings/configuration.toml#L28) contains options to customize the 'describe' tool:

- `publish_labels`: if set to true, the tool will publish the labels to the PR. Default is true.

- `publish_description_as_comment`: if set to true, the tool will publish the description as a comment to the PR. If false, it will overwrite the origianl description. Default is false.

- `add_original_user_description`: if set to true, the tool will add the original user description to the generated description. Default is false.

- `keep_original_user_title`: if set to true, the tool will keep the original PR title, and won't change it. Default is false.

- `extra_instructions`: Optional extra instructions to the tool. For example: "focus on the changes in the file X. Ignore change in ...".
- To enable `custom labels`, apply the configuration changes described [here](./GENERATE_CUSTOM_LABELS.md#configuration-changes)
### Markers template

markers enable to easily integrate user's content and auto-generated content, with a template-like mechanism.

For example, if the PR original description was:
```
User content...


## PR Description:
pr_agent:summary

## PR Walkthrough:
pr_agent:walkthrough
```
The marker `pr_agent:summary` will be replaced with the PR summary, and `pr_agent:walkthrough` will be replaced with the PR walkthrough.

##### Example:
```
        env:
          pr_description.use_description_markers: 'true'
```          

<kbd><img src=./../pics/describe_markers_before.png width="768"></kbd>

==>

<kbd><img src=./../pics/describe_markers_after.png width="768"></kbd>

##### Configuration params:

- `use_description_markers`: if set to true, the tool will use markers template. It replaces every marker of the form `pr_agent:marker_name` with the relevant content. Default is false.
- `include_generated_by_header`: if set to true, the tool will add a dedicated header: 'Generated by PR Agent at ...' to any automatic content. Default is true.