While this seems like an easy mistake to prevent, it is a professional courtesy to ask people’s permission to use them as a reference, so they know to expect a call. If your references respond with surprise and confusion when a potential employer contacts them, it gives the impression that you are unprofessional or disorganised.
An example would be listing someone who had little to no interaction with you on a day to day basis or a reference for a position which is so far away skills wise from what you will be doing in the new role that it would have little significance.
If you don't list different ways that your references can be contacted, it could cost you the job. By giving employers different ways to contact your references could also speed up the whole recruitment process
Your references might be from jobs you had a while ago, and they might not know what you’re doing now. If your potential employer feels like you’re not in touch with your references regularly, they may wonder why you listed them.
You should never ask someone to be your reference if you are not sure what they will say about you, you should know that they will speak glowingly of you.