The test queried 'budget', which only one corpus document matches, so it returned a single-element array with nothing to reorder — it would pass even with the tie-break removed. Switched to 'muller', where docs 1 and 5 tie at the same score and ordering is decided solely by the ascending-id tie-break. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>