We all know Stalin's spy rings informed him of the coming German invasion, which he dismissed as counter intel. He didn't believe them, and feared calling up reserves would be interpreted as an act of aggression by Hitler.
But what if a copy of the operational details of Barbarossa landed on his desk on the morning of 22 June? Something like this is not ASB. During the Phony War a copy of German war plans for France fell into Allied hands, though the plan was radically changed afterwards. During Operation Market Garden the Allied battle plan landed in the hands of the German commander. And of course famously during the American Civil War, a copy of Confederate plans for Antietam was found by Union soldiers.
The war has already started, but now Stalin knows German objectives, time tables, and allocation of forces. How much good would this intel do for the Soviet response?