Port from nearai/ironclaw#7965: BM25 admits any document scoring above
zero, i.e. sharing ONE term with the query. A long descriptive search
for a capability that does not exist therefore returned a plausible-
looking ranked list, and the model read 'results exist' as 'it is in
here somewhere' and rephrased instead of stopping (IronClaw production
trace: 652 tool calls, 216 of them tool_search, hunting a 'data' tool
that did not exist).
A document must now match at least half the query's ANSWERABLE terms
(terms present anywhere in the index) before it is offered. Coverage
only engages from four answerable terms up, preserving recall on short
queries; exact tool-name matches remain authoritative; the substring
fallback is unchanged.
Docs: relevance-floor bullet added to tool-search.md implementation
details.
Teknium
c63de5a231