Check it against the source

Language tools can write sentences that sound right and are not: a quotation nobody said, a date that is off by a decade, a book that does not exist.

The fix is simple and old-fashioned. For anything that matters, find the original source yourself: the document, the page, the official figure. Check the specific claim, not the general topic.

A good rule is to check the one fact that, if it were wrong, would change what you do next.