Level 3 — A multi-agent clinical assistant

By Level 2 the assistant is safe and self-aware, but it's still one generalist. The problem with one generalist over CKD is that the domains pull in different directions: "how much potassium can I have" wants dietary thresholds and a calculation, "is ibuprofen safe for me" wants kidney-safe medication rules, and both want different slices of the guidelines. Level 3 makes each its own specialist.

An orchestrator and four specialists

A router reads the query and hands off to the right agent, then a final step synthesises the result into one reply:

• Knowledge (RAG) agent — general evidence-based answers from the guidelines, with citations.
• Diet agent — dietary guidance with actual calculation for potassium, phosphorus, sodium and protein, not just prose.
• Medication agent — kidney-safe medication guidance and interaction warnings.
• Lifestyle agent — exercise, blood pressure, smoking, stress.

Each specialist is narrower, so it can have a sharper prompt and pull the right part of the knowledge base instead of competing with everything else for the model's attention. The orchestrator's job is just classification and synthesis — the same coordinator-plus-specialists shape I used in the customer-support system, in a different domain.

When the extra layer earns its place

Honestly? Not always. For a plain factual lookup, Level 1 answers just as well and Level 3 is overhead. Where the specialists pull ahead is the questions that genuinely span domains, or where a domain needs to do something — like the diet agent computing against a limit rather than describing it. That's the rule: add an agent when there's a distinct job with distinct logic, not because multi-agent sounds impressive.

Next, the part that keeps all of this honest: evaluation, and results I'm not going to dress up. (Part 6)