Most agencies sit on years of candidates in Bullhorn, Vincere or JobAdder who are invisible to keyword search: the CV says “ran the Iberian channel”, the requisition says “partner sales, Spain”. Meanwhile outreach tools make it trivial to send hundreds of near-identical messages, so candidates have learned to ignore them. More volume makes both problems worse.
The useful version does the opposite. Semantic search over your own database finds the people a recruiter already has a relationship with, described in their own words. A draft message refers to something specific in their history and to why this role might fit, and a recruiter reads it, changes it and decides whether it goes at all. Fewer messages, each one worth replying to.