[jcheng]

I agree that retrieval can take many forms besides vector search, but do we really want to call it RAG if the model is directing the search using a tool call? That like an important distinction to me and the name "agentic search" makes a lot more sense IMHO.

[simonw]

Yes, I think that's RAG. It's Retrieval Augmented Generation - you're retrieving content to augment the generation.

Who cares if you used vector search for the retrieval?

The best vector retrieval implementations are already switching to a hybrid between vector and FTS, because it turns out BM25 etc is still a better algorithm for a lot of use-cases.

"Agentic search" makes much less sense to me because the term "agentic" is so incredibly vague.

[regularfry]

I think it depends who "you" is. In classic RAG the search mechanism is preordained, the search is done up front and the results handed to the model pre-baked. I'd interpret "agentic search" as anything where the model has potentially a collection of search tools that it can decide how to use best for a given query, so the search algorithm, the query, and the number of searches are all under its own control.

[jcheng]

Exactly. Was the extra information pushed to the model as part of the query? It’s RAG. Did the model pull the extra information in via a tool call? Agentic search.

[regularfry]

That's far clearer. Yes.

[simonw]

This is a really useful definition of "agentic search", thanks.