Here's some more feedback on the "more/less" feature after using #7343 for half an hour:

• I think the "less" button/link does not make any sense. When viewing the "short" tooltip, sometimes you want to see detailed description, so the transition short->detailed does make sense. Transition in the other direction does not: I can not imagine anyone looking at the "detailed" popup, and then thinking "Hey, I want to see a short version of this popup".
  Instead, the only thing that makes sense after viewing the detailed version is: closing the popup.
  I suggest: don't show the "<inspection name> less (Ctrl-F1)" title for the detailed popup. Using Escape key to close the popup seems intuitive enough.
• The "detailed" popup should behave a little bit less like a tooltip. For example here are some problems:
  • Moving mouse from outside to inside the detailed popup will close it (I was moving mouse to the scrollbar, because long description didn't fit)
  • Even worse: mousing mouse from label area to scrollbar of the detailed popup will make it disappear
  • When detailed popup is active, I'd expect Up/Down/PgUp/PgDown to operate on inspection description. Instead they operate on editor.
• The point is this: by invoking the "detailed" popup (using Ctrl-F1 or otherwise) I have explicitly indicated to IDEA that I'm really interested in viewing/reading the longer description. At that point I would expect IDEA to let me read the action description without hiding anything or performing any other smarts. The experience should be similar to explicitly invoking Quick Documentation (but using a more minimal interface).

I'm not sure if above ideas are the best solutions. However, please do think about/work on this feature before release. Inspections are one of the crown jewels of IDEA, and it would be a pity if the underlying richness would be limited by the UI.