Well played! yep, it says it in the description, it refills the energy of the workers in the lower levels. So if you have 4 coffees it refills the energy of the 4 workers closest to the bottom.
Yeah, sorry, it's hard to convey what it does, it's not ONE coffee per day, it's ONCE, like in "you could use that buff once per day", and the buff affects multiple workers. Do you think there could be a better way to phrase it? it's just a caption I could modify it, no problem, I'm open to suggestions if it's more clear for the players. Thanks!