Hi Martin, I kind of generally try to avoid tooltips for important information (like describing what a particular control actually does), because it leads to a kind of unpleasant herky-jerky workflow where you have to do stop everything and pause over top of various bits of UI to see what they actually do.

So it's a big focus with MoI in general to try and put some description of what a button does up right on the button itself, rather than a tooltip. That way the UI becomes more sort of "browsable" where you can do just a quick visual scan over it and see what things do right away.

However, having said all that, tooltips can work well for a kind of supplemental or extended information, and that aspect could be a good fit for this case. So something like 3/160 seems like it could be a good possibility to have on a tooltip.

The selection indicator itself (some indicator showing if all nothing / everything / partial objects in a slot are selected) would probably be good though to have right on the top level because then along with giving some of the basic level feedback it would also be a natural place to click on to do selection actions as well.

- Michael