As we near a close on the famous "pilot season", I can't count the number of actors who have told me how they got to the CDs room and because the reader wasn't as expected, they looked to the reader as to how to tell their story. It is so important to use the reader, but to use the reader as a motivator rather than a director. You have a passion for this story. Get the reader to share that passion. Let the reader see what you love about the film/TV show they are casting.