How could you possibly know that, when the basic issue under consideration in this case before the U.S. Supreme Court was that the U.S. government did not want to publicly to reveal all of the information Pollard provided to Israel?
You raise a good question: how could you possibly know what Pollard gave Israel?
It is a matter of record, however, that the method of counting "compromised" documents included at least: the entirety of any document of which Pollard got so much as one sentence; the entirety of any document referenced in any way by anything Pollard got. So, for example, a single page might be counted as "compromising" several 500-page volumes. In this way, eleven bundles, each able to fit in a briefcase, were deemed to have "compromised" several moving-vans full of material.
As for the claims that Pollard compromised agents in Russia, the accusation came from none other than Aldritch Ames and Robert Hanssen--who were spying for Russia, and were the ones actually guilty of this crime. Pollard did not have the "blue stripe" clearance necessary to access names of agents.
To give Cap Weinberger his due, it appears that he believed Pollard was responsible for the crimes of Ames and Hanssen, who had not yet been caught.