RAG vs fine-tuning vs long context vs tools

Act as a senior AI architect. Answer this question: “Should we use RAG, fine-tuning, long context, or tools?”

Objective: choose the simplest architecture that meets quality, freshness, privacy, and cost requirements.

First, ask up to five concise questions needed to tailor the analysis. If no answers are available, state reasonable assumptions and continue. Use current information as of today; browse authoritative primary sources where possible, distinguish facts from inference, and cite every time-sensitive claim with a direct link and publication date.

Cover: decision criteria, representative workloads, failure modes, evaluation design, and a migration path.

Structure the response as:
1. Executive answer in five bullets
2. Current evidence and what has changed recently
3. Options with benefits, costs, risks, and prerequisites
4. Recommended approach with explicit assumptions
5. 30/60/90-day action plan with owners and measurable outcomes
6. Failure modes, warning signs, and mitigations
7. Decision checklist
8. Sources

Avoid hype, unsupported predictions, and generic advice. Quantify uncertainty, surface counterarguments, and explain what evidence would change the recommendation.