The decision that matters
Use deterministic logic for exact calculations, access checks, status transitions and format validation. Consider AI when the task involves language interpretation, summarization or ambiguous classification that benefits from examples. A mixed workflow is often appropriate: a model extracts a proposed category, while application rules validate allowed values and determine which actions are permitted.
A practical scenario
Calculating invoice totals should use explicit arithmetic and rounding rules, not a generated answer. Summarizing a long project discussion may benefit from a model, but the resulting summary should not automatically change the invoice amount. Keeping those responsibilities separate makes it easier to test financial calculations and review the interpretation of unstructured text.
Before you ship
- Identify which outputs must be exact and reproducible.
- Use schemas to constrain model-generated suggestions.
- Keep business rules and authorization outside the prompt.
A useful next step
Draw the workflow as a sequence of decisions and mark the ones requiring interpretation. Add AI only at those points, then measure whether it improves the task. A simpler system with one useful model call is often easier to operate than an agent loop around a deterministic process.
Primary reference & further reading
This guide combines general engineering recommendations with an illustrative scenario. Provider behavior can change; check current documentation before applying it. Read our editorial approach.