Maybe a useful concept to adopt here is the DRI - Directly Responsible Individual, which is apparently a term first used by Apple. The GitLab Handbook has a good definition: https://handbook.gitlab.com/handbook/people-group/directly-r...
"ultimately accountable for the success or failure of a specific project, initiative, or activity"
I think that role should be reserved for a human, who can then use all the agents they like but has to take accountability for what is ultimately delivered.
It should be reserved for a human because humans have time preference. An AI will wait for your prompt for a billion years. It can get turned off and found by alien archeologists a million years in the future, turned on and it won't notice. Biological entities care about time a lot though, and it is at the core of most human ethics and values and ultimately real and can't be denied. Even the most ardent solipsist or moral relativist fears spending years in prison.