The same questions, answered three different ways: plain search, a smarter hybrid search, and a full agent. Each one runs over the same set of clinic documents. For each, you can see what it pulled up and why, the answer it gave, and how it scored. The surprising part is that no single way wins every time.
0.975
dense MRR
0.829
hybrid MRR
On this clean corpus dense retrieval won outright and hybrid hurt it, because BM25's keyword arm added noise where the embeddings were already crisp. Hybrid only pulled ahead on rare tokens and acronyms. Agentic was the only thing that could complete an action. The takeaway is not 'use hybrid' or 'use agents' — it is that the right retrieval strategy depends on the query.
Naive RAG (dense)best here
Retrieved · top 3
#1 · foam-sclero · relevant0.94
Foam sclerotherapy injects a foamed sclerosant under ultrasound guidance to collapse and seal a varicose vein.
#2 · laser-rfa0.58
Endovenous laser (EVLT) and radiofrequency ablation (RFA) close larger varicose veins.
#3 · varicose0.51
Varicose veins are swollen, twisted veins, most often in the legs, from weakened valves.
Answer · 1 tool call
Foam sclerotherapy injects a foamed sclerosant into the vein under ultrasound guidance, which collapses and seals it.
recall@3
1.00
MRR
1.00
faithfulness
0.98
task done
yes
Right chunk at rank 1. Nothing to improve here.
Hybrid (BM25 + RRF)
Retrieved · top 3
#1 · laser-rfa0.031
Endovenous laser (EVLT) and radiofrequency ablation (RFA) close larger varicose veins.
#2 · foam-sclero · relevant0.029
Foam sclerotherapy injects a foamed sclerosant under ultrasound guidance to collapse and seal a varicose vein.
#3 · phlebectomy0.022
Ambulatory phlebectomy removes bulging surface varicose veins through tiny incisions.
Answer · 1 tool call
Foam sclerotherapy uses a foamed sclerosant under ultrasound to collapse the vein.
recall@3
1.00
MRR
0.50
faithfulness
0.95
task done
yes
BM25 noise bumped the right chunk to rank 2. Correct chunk still present, but ranked worse.
Agentic RAG
Retrieved · top 1
#1 · foam-sclero · relevant0.94
Foam sclerotherapy injects a foamed sclerosant under ultrasound guidance to collapse and seal a varicose vein.
Answer · 3 tool calls
Foam sclerotherapy injects a foamed sclerosant under ultrasound guidance, collapsing and sealing the vein.
recall@3
1.00
MRR
1.00
faithfulness
0.98
task done
yes
Correct, but it reasoned and re-queried for a lookup that needed one shot. Right answer, wasted budget.
Why Naive RAG (dense) wins this one
A clean semantic lookup. Dense embeddings already separate this perfectly, so naive RAG puts the right chunk first. Hybrid's BM25 arm matched the common word 'work' across other chunks and, after RRF fusion, pushed the correct chunk from rank 1 to rank 2 — the MRR 0.975 -> 0.829 drop in miniature. Agentic got the right answer but spent three model calls on a one-shot question.
Want to watch the agent actually book the appointment, step by step? Play with it in the agent sandbox.