Should I put an AI agent in my product, or is a simple workflow enough?

A workflow follows steps you defined with the model filling in the reasoning slots; an agent decides its own path with tools in a loop. Workflows are cheaper, faster, and debuggable, and they cover most real product needs (tagging, drafting, summarising, extracting); agents earn their complexity only when the path genuinely cannot be known in advance. Both OpenAI and Anthropic say the same thing in their own guides: start with the simplest thing, add autonomy only when a measured need appears.

A quick orientation. The real value is below: resources worth your time, from people who've actually done it.