From Longman Dictionary of Contemporary Englishtough/smart cookietough/smart cookieinformalINTELLIGENT someone who is clever and successful, and knows how to get what they want → cookie
Examples from the Corpus
tough/smart cookie• The Gingerbread Man Summary A fox ate a smart cookie.• Mr Kinnock is clearly a tough cookie.• Unless Newman is a smart cookie.• Barney's a tough cookie. He knows how to play politics.• Monroe herself, of course, was a smart cookie, but she knew enough to play dumb.• Now, women on television are depicted as tough cookies who need a man like a fish needs a trouser press.• Being a dedicated tough cookie, he has delivered the goods in impressive manner.• In general, the provincial circuit is a far tougher cookie than its metropolitan counterpart.• We're tough cookies here, and so are you. 