His job is to manipulate Penny to keep her working for the TV show, no matter what. He also tries to lure her away from Bolt, describing the studio as Bolt's "world". He claims that he would trade Penny for his daughter in a heartbeat. When Bolt disappears, he wants Penny to work with another dog.
During the fire on the set, the Agent re-encounters the real Bolt, tripping over the dog while fleeing. After Penny and Bolt are rescued from the fire and taken into an ambulance with her mother, the Agent joins them and tells Penny's mother that Penny could still do the show even when injured so he can earn money. He is immediately thrown out of the ambulance by Penny's mother, who announces to him that she and Penny quit. He tries to talk them out of it, but Penny's mother slams the ambulance door in his face. He presumably becomes the agent of Penny's replacement afterwards or he got fired.
The Agent is only bothered about the TV show and not about the real lives of Bolt, Penny and her mom to the extent that he is unsympathetic, abrupt and a bit greedy for money. When Bolt goes missing, the Agent even goes as far as to try and trick Penny with a dog resembling Bolt. His catchphrase is "Let's put a pin in it", which he uses to end conversations that he would rather not discuss further.