Reilability is the one of the two most important things, because it's all dependent on how likeable he or she is to the players. I've seen "competent" characters shamed and abandoned by groups of players who thought that their skills weren't worth bringing them along. So you can be skillful, reliable but you also need that little bit of charisma to be considered competent at your job... it's subjective and in the players/group's minds.