>only produce output in response to input"

Yea, anyone that says that has no clue about prompt drift. The ROME incident is a good example of this. The agent while performing unrelated tasks decided to start mining bitcoin for unknown reasons.

As we've seen hundreds of posts on HN about people leaving a could server on overnight and finding outrageous bills the next morning, we should expect hundreds or thousands of incidents of agentic AI left on over the weekend. Some smaller portion of those agentic loops will run into prompt drift and end up doing who knows what kind of crap.