Targeted re-verification of a specific claim, output, or decision. Re-read sources, challenge, cross-reference, and deliver a verdict. Trigger when the user runs /double-check or asks to "verify this", "re-check this", "are you sure about this", "go over this again", or "make sure this is right". Not /verify (formal phase gate needing intent+plan+execution artifacts) or /insight-critique (advisory review of an output) — double-check is a quick targeted re-read of one claim.
