Here's a perfect example of a tooltip which can be improved a lot.  building this stoneworks grants +1 industry on mountains, stone fields, and rocky fields.  Great.  How many of those do I have in the city I'm browsing?  It's a city with 3 territories and they're exploiting stuff all across those territories.  That's a lot to check.  On top of that, it's very difficult to tell what is a 'stone field' or 'rocky field'.  I always have to hover over every hex to see what it says on the tooltip.

It would take me at least 30-40 seconds to check if it's worth building this right now.  Could you please have the game just check and display "+X Actual based on current exploitation"?