I am currently going up the Halo Reach commendations and I have a doubt, the Needler T33 used by the Grunts (Unggoy), Jackals (Kig-Yar) and Elites (Sangheilis) of Covenant is an automatic weapon, semi-automatic or warlike material ?
I’m not sure what you mean. The Needlers used by grunts and jackals fire semi-automatic (one trigger pull means one shot), while Elites and Skirmishers seem to fire them fully automatically (at least, this is what I think).
It will count towards your automatic weapon commendation for each kill you get with it. Try and fire short bursts with it though (enough to get a supercombine explosion) as to not waste too much ammo on each target.