How can I tell if a drill clutch has been damaged?
I would not worry about it because it still works, but is no longer brand new
I have multiple dewalt drills and multiple impact drivers that have had the clutch trip probably 1000 times or more on the impacts. is there a little play?  Yes more than when new, probably, possibly.
Do I worry about it?
Nope they still work both at home and at work, when they don’t work any longer I will worry about it.
It’s kind of like a clutch in a car but here there is no adjustment right. When it will no longer work you then know it’s worn out.
It will take a long while based on my experience my drill and impact at work are 6 years old regular use, home ones older but kids and grandkids abuse and they all still work.