The Washington Post writes about this, citing its sources. However, it is not specified what kind of information the agents were trying to find. It is also unknown whether it is a question of nuclear weapons of the United States or another country.
Recall that the lawyers of the US Department of Justice filed a petition for permission to publish the warrant and inventory seized during the search. Justice Minister Merrick Garland said he himself sanctioned the decision to seek court permission to issue a warrant.
Trump announced the search on Monday evening. He also noted that he had not been warned about the impending search. He accused law enforcement officers of political persecution. In addition, Trump announced that "nothing like this" had ever happened to any US president before. Trump was especially outraged that agents even broke into his safe.
It is known that early on the morning of August 8, when the agents raided the residence, Trump was not at home. Most of the security forces were focused on the part of the residence where Trump's offices and personal premises are located.