No game provides tool tips for every aspect of everything in the game. This is why the Internet was invented, so that we could have wikis to give us all the info.
https://bg3.wiki/wiki/RageUnderstandale, but this confuses many people early on who are not familiar with DnD. It's not an advanced level mechanic that you need to figure out on your own. Early game mechanics like this should be labelled I think, as it's a pretty big deal. It would certainly save people time because they, like me, bought heavy armour, specced into heavy armour, and then realised that was all for nothing.
And if nothing else, it's a suggestion.
