The Github link has a detailled description of what it can do.
Basically, there are triggers and actions.
Currently there are these triggers:
Find posts with duplicate URLs
Find posts/comments that match a regex pattern. Posts can match on URL, title and content, comments only on comment. This trigger can also be used to find posts/comments that don’t match the regex.
Actions:
Post a comment under the post/comment
Lock a post
Remove a post/comment. For this action you can also post a reason.
The actions that create text (posting a comment and the reason for removal) allow you to fill in any information that the REST API returns for the target post/comment. This allows you to e.g. address the user by name or link to the already existing post of the duplicate url.