Good write up on Art Direction versus Design here.
"To me, an art director has the very difficult task of (working either directly with a client or a creative director) to decipher the needs of a client. This could be going through a script, brief or conversation to understand what the design and communication objectives are. They have to relay this to the client, gain their trust and win the job in a competitive pitch situation.
There are a lot of interpersonal or “soft skills” needed to do this. They have to demonstrate an ability to ask great questions, remain objective, listen intently, parse wants from needs and convert vague language (e.g. “cool,” “organic,” “epic”) into a shared visual language. This is the first challenge and not everyone is cut out to do this."