Answer: It is difficult to say whether the Pardoner is good at his job because it is unclear what his job actually is. In the text, the Pardoner claims that his job is to teach others not to be greedy, but his actions throughout the story suggest that he is actually a con artist who uses his knowledge of people's greed to exploit them for his own financial gain.
For example, the Pardoner openly admits that he preaches against greed and avarice in order to trick people into buying indulgences, which he claims will absolve them of their sins but are actually useless pieces of paper. Furthermore, the Pardoner shows no remorse for his dishonest behavior, and even boasts about his ability to deceive people.
Given the Pardoner's dishonest and self-serving behavior, it is doubtful that he is successful at teaching others not to be greedy. In fact, his actions may actually encourage people to be more greedy, as they may see his success at exploiting others as proof that greed is a beneficial trait.
Overall, it is clear that the Pardoner is not a good teacher or moral guide, and it is doubtful that he is successful at his job, whatever that job may be.