What happensThe search provider allows 250 queries a month. When it runs out, the chain falls back to a headline feed that ignores site: operators entirely. Jobs that depend on searching specific domains keep running and keep returning results, just not from the domains they asked for.
EvidenceMeasured per job by reading the provider's counter before and after a single run: 22 searches for one job, ~36 for another. Against a 250/month allowance and two daily jobs, exhaustion is arithmetic, not bad luck.
Why nothing caught itThe degraded path returns results. Something that returns plausible output is far harder to notice than something that returns nothing.
CostTargeted research becomes untargeted, with no visible change in behaviour.
FixA second real provider with a 2,500/month allowance inserted ahead of the headline fallback, plus a balance check that alerts when projected burn exceeds the remaining month.