In the portal there is a section for "Filter by status". Sometimes those statuses need some explaination and there is a description for each status to use as a tooltip in the same way you show tooltip for idea categories.
I think this feature is really simple for you to add. For my organization it adds big value and will make the portal easier to understand.
Thank you for your idea. It is currently possible to customize the design of the ideas portal. This could be accomplished by adding a link to more details on the various statuses. This article provides more guidance on advanced portal design.
Given the current customization options and other priorities, we are unlikely to implement this idea at this time. We hope you understand.
Agreed with Joakim. It would be valuable and consistent with the way descriptions for categories are displayed.