You
What makes an error message good?
ChatGPT
It names what failed, what was expected, and what to do next. "Invalid input" fails all three; "expected a date in YYYY-MM-DD, got 12/03/2026" passes the first two and hints at the third, which is usually enough.
You
Is there a simpler version that gets most of the benefit?
ChatGPT
Yes: do the first step, skip the automation, and revisit in a month. Most of the value is in the first step, and most of the cost is in making it repeatable before you know it is right.