Well, acid techno (as defined by the london sound, which is where it started [not acid, but Acid Techno, before you historians go nuts]), has a definate format, which hasn`t changed too much since Routmaster 1 and other earlier releases.
It has a very defined structure, beginning, breakdown, mad bit, outro.
Normally very 909 based percussion, not too sample-loopy, with analogue basslines and synth stabs on the abrasive side.
Generally, it has a 303 but not necessarily, they generally build, and take you somewhere. It`s most easily recognised by the attitude of taking the piss, and screw authority etc.
But I generally still recognise it by the very "909-ey" percussion, hard house tempo`s and the fact it generally builds.

I wouldn`t say power tools was hard techno though, it`s Ants acid techno, and follows all the above statements.