astute, scheming, smart, conniving, sharp, calculating, hard, calculative, clever, knowing, more...

foolish, silly, stupid

cagey, wily, sly, slick, foxy, astute, guileful, clever, more...

astute and clever,   not easily duped,   more astute,   not easily tricked,   most astute,   harder to fool,   tough to trick,   silent and clever,   cagily observed,   smart moves