Bread flour would probably only make the cookies a bit tougher but not drier. I find a lot of cookie recipes make too dry of a cookie for my liking so I add sour cream. To a recipe that calles for around 2 cups of flour I add 1/4 cup of sour cream. Like in chocolate chip cookies. It softens the cookie but lets the outside edges be nice and crisp. Also overbaking is the main culprit in dry cookies. Always take them out when the edges are turning golden brown but the centers are looking not quite done. Let me know if this helps. I am always curious if others find this useful.