Write it in plain English
Describe the rule the way you'd explain it to a colleague. The local LLM drafts a decision table with inputs, outputs, and rules. You review it and change any cell by hand.
New decision
Decision policy
A loan is approved if credit score is 700 or higher, age is between 21 and 65, and income is at least €10,000. Scores from 650 to 699 go to manual review.
The prompt should be a clear and comprehensive statement of the decision policy.