In The Odyssey by Homer, Odysseus's craftiness is both good and bad. As an epic hero, Odysseus is a quick thinker and a resourceful survivalist. This is shown throughout the epic, but notably in the cave of the Cyclops, Polyphemus. The results of his craftiness wind up being catastrophic.
When the Cyclops asks Odysseus his name, Odysseus is quick to respond, "Nobody." He tells the Cyclops, "My name is Nobody: mother, father, and friends, everyone calls me Nobody," (Book IX, lines 397-398). This comes in handy later when Odysseus has the idea to blind the giant with a steaming hot poker.
As the Cyclops gropes about and screams in agony, gripping his bloody eye socket, his fellow Cyclopes attempt to come to his aid. They ask, "What ails you, Polyphemus? Why do you cry so sore in the starry night?" (Book IX, lines 437-439). Of course, Polyphemus only has the name "Nobody" so that is what he tells them. "Nobody, Nobody's tricked me, Nobody's ruined me!" (Book IX, Line 444). This sends the other Cyclopes away in confusion, keeping Odysseus and his men safe from any punishment they may have received for their evil doings. In this way, Odysseus's craftiness is a benefit to him.
However, because he and his men escape the Cyclops's cave by cleverly hanging on to the underbellies of the sheep, Odysseus's sense of pride becomes over-inflated and he begins to taunt Polyphemus from the safety of his ship. "How do you like the beating that we gave you, you damned cannibal? Eater of guests under your roof!" (Book IX, lines 521-523). And unfortunately, his hubris gets the better of him, because Odysseus continues to tease the giant Cyclops, even after his men beg him to stop.
He eventually ends up giving his real name to the Cyclops, because he is so proud of his deeds. "Cyclops, if ever mortal man inquire how you were put to shame and blinded, tell him, Odysseus, raider of cities, took your eye: Laertes's son, whose home's on Ithaca!" (Book IX, Lines 548-552). In doing so, he opens himself up to the wrath of Poseidon, father of Polyphemus, and effectively makes his journey home tremendously difficult.
In this case, Odysseus's craftiness is a hindrance.