I am frequently contacted by persons who want to know what it takes to be an agent, what it is like to be an agent, how to go about being an agent, how did I become an agent, etc.
Most agents have a law, business, or combined background and experience.
Knowledge of the sport and the business behind the sport. Each sport operates differently and this unique quality determines how each sport has to be approached when representing athletes. Know who the decision makers are - whether a coach, GM, team owner, etc. The registration or certification of certain player associations - without this you cannot even start to talk to a team about a contract. You have to first apply and pay the set fees and charges.