A one-shot graph ranking diffuses over the whole neighbourhood; a question
whose answer sits two hops away is better served by following the edges. The
graph_search tool gives an agent search_entities, get_relationships and
read_entity_pages over its graph sources. On a multi-hop corpus where the
bridging entity is never named, answers went from 0/10 with classic vector
retrieval to 10/10 with the tool, end to end through /stream.
The tool has no setting of its own. It is offered exactly where the agent can
already search: agentic and research agents always, a classic agent only for
sources exposed as a search tool. A graph source left at prefetch is used for
ranking only.
Tests now pin GRAPHRAG_ENABLED to its shipped default, as CI has: with a dev
.env enabling it, every agent test's graph check read the developer's real
database and left a pool to it behind.
Alex
6b9b193337