Chicken breasts can easily dry out. Leaving the skin on until done and making sure you do not overcook it helps a great deal. The breasts should read 160 degrees on an instant reading thermometer and the juices run clear. By leaving the skin on while broiling it keeps the breast moist and flavorful. It is important to broil the chicken breasts no closer than the 7 inches from the heat as recommended. This will give the breasts a chance to cook throughout without burning on top and drying out. Placing it in a very hot pan seals the bottom and retains more moisture.