It might be okay, but you can never really have a 100% answer with fish injuries. Dragon gobies are actually hardy, but like any fish, they can be fine one moment and dead the other. Leave it to itself... and it might make it through. I've had oscars, bichirs, butterflyfish, shiners, darters, etc. jump out and come close to drying out, survive.
Good choice on adding the cover. DG's are notorious jumpers, along with anything "eeley." More so because they hang onto the tank wall, with their heads out of the water a large amount of the time. Curious fish
I'd comment on your tank stocking... but i'm sure someone else will post some lengthy hissyfit about it soon hehe.
Good luck with your fish
