I think every team wants its members to be reliable. Being reliable means that you can be depended on by others. This usually means that our word is trusted and that we deliver on what is promised. Teammates that struggle with reliability lose trust very quickly. I don’t think that anyone wakes up in the morning with the goal to let someone down. When I have let someone down, I know that I got up that morning intending on delivering, but choices to compromise my work ethic made that impossible. Reliable teammates know what to say no to. They know that everything they want to do must not be prioritized over everything they must do to remain reliable.