`best_available_score` was added by #3670 so a bar could be judged from
what it rejected, and it arrived null on four unrelated causes: the corpus
offered nothing, the query was empty, the embedder was down, or the
DATABASE QUERY FAILED. Only the first is a measurement. The fourth is the
#2663 shape — a swallowed failure rendering as a clean zero — inside the
field added to fix an instance of the #2663 shape.
Found while trying to explain why reuse_slot returned nothing on 45 of 45
calls, and auto_inject on 153 of 161. That investigation is still open;
what it established first is that the readout could not answer it.
THE FIX IS NOT A NEW COLUMN. A call that never searched writes no row, so
every remaining null means one thing: searched, and nothing came close.
That is the convention the pre-tool arm already follows for a blank
command — "a row here would report a call that never happened and drag the
clear-rate down with phantom declines" — extended from the case a caller
can see in advance to the ones only the search knows about.
Both searches stamp `report["searched"]` FALSE before anything can return
and True only where a real result set exists, so every early return leaves
it false. It has to be the first thing done to the dict: a return added
above that line would leave the key absent.
ABSENT IS A THIRD STATE AND IT DEFAULTS TO TRUE. A caller that passes no
report cannot know, and the safe reading there is the old behaviour. Only
a real search can report False, so absent means "nobody asked" and never
"it failed" — which is also why 66 existing mocked searches across twelve
test files keep working unchanged rather than being rewritten to simulate
a flag they do not care about.
A FAILURE IS NOT MADE INVISIBLE. semantic_search_notes already logs a
WARNING on a query failure, which is where a broken search belongs: a
counter cannot say "I am broken" without a reader already trusting it.
Three tests, and the middle one is what makes them discriminate — a
blanket `return` passes the first and fails the second, because a call
that searched and came back empty is the only evidence a threshold is too
high (#3497).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011cPyzNnegXHr5iRMzzy5KJ
bvandeusenandClaude Opus 5