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What is Recall and precision?

Verified 5 August 2026

The two trade against each other. Returning more results raises recall and lowers precision; returning fewer does the opposite. Which one to optimise depends entirely on who is reading the results.

Human search engines optimise recall and rank: a person skims and discards, so a hundred results with the good one first is a fine outcome. Agents cannot do that — every irrelevant result costs context and reasoning tokens. For agent retrieval, precision dominates.

That inversion is the argument for admission control: move quality from query-time ranking to index-time admission, and return fewer, better things.

How unlob handles this: How it works

Common questions

What is Recall and precision?

Recall is the share of relevant documents a search returns; precision is the share of returned documents that are relevant.

How does Recall and precision work in practice?

Human search engines optimise recall and rank: a person skims and discards, so a hundred results with the good one first is a fine outcome. Agents cannot do that — every irrelevant result costs context and reasoning tokens. For agent retrieval, precision dominates.

See it working

The free tier is 10,000 requests a month with no card — enough to test any of this against your own queries.