Forget human metaphors for software agents. Why not God metaphors?
Here's a paper that actually tested this! (Jung et al, CHI 22, https://dl.acm.org/doi/fullHtml/10.1145/3491102.3517653 )
Sample dialog from their protocol: "Greetings, I am the lord thy god. You shall help researchers at a university by participating in this research."
Their deadpan conclusion:
"an agent metaphor that locates higher than Human in the Great Chain of Being framework may disappoint workers in the system's ability due to high expectations"