Is the pilot a human or humanoid? If so it seems large for a simple fighter. But that also means more room for batteries or munitions.
There isn't much for making it agile. I suggest adding some kind of single- or double- nozzle stabilizer propulsion nozzle system to the front, probably behind and below the cockpit. If it is truly a propulsion system and it has a variable angle, so long as the g-forces and inertia don't kill the pilot it will outfly anything else.
I like your design. SO many people put the cockpit to far back not thinking about pilot sight-lines and add to many fiddly bits that would also interfere in that way. But here you have made a simple yet very elegant fighter that is very nice to look at and seems flightworthy.
Pretty kick ass design! I'd fly that if only I didn't feel nauseous when doing spinning moves. Well as long as I don't have to spin in it *shivers* just thinking about spinning is making me nauseous. Oh boy, think non spinny thoughts. Think flying straight. XD