All of life is a series of negotiations. Those who can negotiate more effectively come out ahead. This is true whether you are discussing your compensation when joining a new company or whether you are hashing out what you work on.

If your manager asks you to do something, ask them how the thing they are assigning will help advance your career. Ask the manager how -- if you deliver on what they ask -- they will go to bat for you when they are sitting in the room with their peers justifying your evaluation score. Be willing and able to simply state, "I don't know how you can expect me to spend my time and energy on something that won't help me advance my career." If your manager can't understand or respect that, then that's great! You have a clear warning sign that it's time to fire your manager.