Milestone 399 step 4. A rule and a preference are not equally served by one
ranking, because their losses are not equal:
- a RULE crowded out at the prompt boundary still fires at an act arm. A
push reaches pre_tool_rule, a write reaches write_path_rule. The prompt
hit is a preview of a second chance.
- a PREFERENCE about how to answer has no second chance. The response IS
the act, so crowded out there it is never delivered at all.
A straight ranking therefore favours the record whose loss is recoverable
over the one whose loss is total, and does it INVISIBLY: the rule that won is
a legitimate hit, the telemetry reads healthy, and the only symptom is a
preference that quietly never arrives. reuse_slot exists for the same shape
one corpus over (#2463).
`semantic_search_rules` gains a `kind` filter, so the slot's query can only
answer with what the slot is for. Verifying afterwards would be weaker — an
unfiltered search that happened to return a rule would spend the slot on it,
and that line would be indistinguishable from one that earned its place.
THE SLOT BUYS POSITION, NOT A LOWER BAR, matching reuse_slot. A weak
preference cannot buy it, so silence stays the default. The task asked for a
separate threshold; I did not add one, and the reason is that the worry
behind it — reading a miss rate as a fact about preferences — is answered by
`preference_slot` being its own logged source, where best_available_id names
which preference was refused. A knob added on a guess is a way to
misconfigure the surface; a bar moved on evidence is an argument. The
evidence arrives on its own now.
IT EXTENDS, IT NEVER DISPLACES — and here it parts from reuse_slot, which
evicts its menu's weakest hit. A displaced hit sits in prompt_rule's
retrieval_logs row while never being surfaced, so that source's two tables
stop agreeing and #3668's identity breaks for a reason nothing in the data
explains. Milestone #379 is what losing that identity costs: five steps
planned against two counters disagreeing, not a write path dropping rows. One
extra line in a rare case is the cheaper price.
It also runs BEFORE the bail-out. An empty general result is not proof no
preference qualifies: that search overfetches by distance then collapses, so
a preference ranked below the window is invisible to it while a kind-filtered
query finds it at once. Bailing first would make the slot dead in exactly the
corpus it exists for.
One existing assertion repinned from a bare call_count to a per-source
filter: the slot logs its own query on the same call, and a count would pin
the number of arms rather than the property — going red the next time one is
added, which is rule 167's false alarm about the thing it protects.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011cPyzNnegXHr5iRMzzy5KJ
bvandeusenandClaude Opus 5
d5f96563fd