The "it is my job" response is a bit hard to interpret. Is the interviewee supposed to be intentionally obtuse?

The interviewer's motivation is easy to maintain, but the interviewee's motivation might become challenging if this is just a conversation with the goal of specificity and external topic control. If I know that my interlocutor is supposed to ask me questions to make me more and more specific, I might jump the gun, leading off with "I am a human employed in the care of plants selected for their decorative or nutritive value, and at present I care for carrots, beets, and daisies" rather than "I am a gardener."