you definitely can pull them with a 1/2 ton, but you should be aware of the risks that come with it...
the newer 1/2s have more hp and tq than most of the earlier pulling trucks, but are generally built for a smooth ride and better gas mileage... the newer 1/2s will normally run rear end gears that will yield the best mileage along with a tow mode which switches the tranny shift points to be able to pull heavier loads to compensate for the rear end... the one thing that is not easily adjustable is the suspension... the 1/2s are set up to ride smoothly to compete with the suv and crossover market, and are not easily switched, yet...
if you are gonna pull a few times a year on relatively flat roads at reasonable speeds, you should be fine with any full sized 1/2... if you are gonna pull near max weight through the mountains, at high speeds, or in generally windy areas, maybe not... even though the 1/2s with towing packages come with tranny coolers, and adjustable trailer brake controllers, you might want to look at a 3/4 for the additional safety of the heavier suspension...
fwiw, i would rate the toyota 1/2s more like the big 3s 3/4 tons for towing capability, along with the mileage of a 3/4 with pulling gears... i just don't understand why toyota doesn't drop a mileage motor and highway gears in their 1/2s, and build a 3/4 with slightly beefed up suspension from what they run in their 1/2s... imo they could dominate both markets...
good luck...