Most regular cookies are crisp on the outside and soft or chewy on the inside. Sugar cookies are softer but not soft. While they are not necessarily delicate, they can be broken easily.  And if over-baked, they can be brittle but still delicious to eat. Cookies become hard as they cool, so it's always a good idea to keep an eye when baking.  Ideally, they should not have any brown edges. Perhaps a light color around the edges. Also, leave them on the hot tray for a good 5 to 7 minutes, so they continue to cook and hold their shape.