The skill amounts to determining "what information is required for System A to achieve Outcome X." We already have a term for this: Critical thinking.

In the short term horizon I think you are right. But over a longer horizon, we should expect model providers to internalize these mechanisms, similar to how chain of thought has been effectively “internalized” - which in turn has reduced the effectiveness that prompt engineering used to provide as models have gotten better.

Non-rhetorical question: is this different enough from data engineering that it needs it’s own name?

Not at all, just ask the LLM to design and implement it.

AI turtles all the way down.