I read @Luckyde's comment in another thread
This has given me some lead on how to use the capo tool in simple scenarios.
I guess the name has also to do with the capo in guitars that helps you transpose a chord, but still it's a bit fuzzy - so any help is appreciated.
So rephrasing @Luckyde's answer (trying to fit it in my head at this late hour), one could say that the capo is the way of choosing where the new tween begins, by automating the creation of keyframes for all the affected properties.
Is that truly all there is to the capo tool?