It is hard and brittle. High tensile strength yields hardness but lacks toughness. A good example of high tensile strength is a Black Weapon Hook which has a very hard point and will not deflect up to the point at which it snaps. This style hook cannot withstand any shear pressure. It's sharp and it will stay sharp but you can snap it between your thumbs.
Heat treating to yield tensile strength is a funny creature.
But, you can snap that same bolt with a 6-inch Allen wrench. Chromolly steel and some stainless alloys are, on the other hand very tough. Such a hook will bend some without yielding. A hook that bends past its yield point is then, in a word, bent. I like to spoon fish for wintertime bass and stripers.