How to implement the "more" button/expansion in an inspection problem?

If I add a problem to the ProblemHolder through registerProblem, then when I see an error in an app when the plugin is run, I will see the text I added via registerProblem if I hover over the problem. Additionally, there will be a "more" button at the end.

If I press on this, it just says "Inspection info:Under construction". I want this to show a custom String. How do I do this?

As far as I can tell, this is either a HintAction or a ToolTip Link (InspectionDescriptionLinkHandler), but I have no idea which one to use, or how to use them to do this.

Thanks!