Looking at https://tip.golang.org/cmd/go/#hdr-Generate_Go_files_by_processing_source right now:

Usage:

go generate [-run regexp] [file.go... | packages]

However, at the bottom it mentions:

It also accepts the standard build flags -v, -n, and -x. The -v flag prints the names of packages and files as they are processed. The -n flag prints commands that would be executed. The -x flag prints commands as they are executed.

The usage line should be updated to mention those additional flags:

-go generate [-run regexp] [file.go... | packages]
+go generate [-v] [-n] [-x] [-run regexp] [file.go... | packages]

Other commands have their usage complete and do not skip -n and -x flags that are available, for example:

go clean [-i] [-r] [-n] [-x] [build flags] [packages]
go fmt [-n] [-x] [packages]
go tool [-n] command [args...]
go vet [-n] [-x] [build flags] [packages]
go get [-d] [-f] [-fix] [-insecure] [-t] [-u] [build flags] [packages]

It seems -v is never included even if available, so maybe it's most consistent to do:

go generate [-n] [-x] [-run regexp] [file.go... | packages]