I've Never Met A Perfect Manpage

Lots of manpages are written poorly or incorrectly.

Many just have [options] in the synopsis, and you have to read the whole description
Some fail to italicize or emphasize variable as opposed to constant arguments. Some do so, but wrongly or inconsistently. (troff is not easy)
Some display multiple options as separate forms of the command.

You may need to read the description because somebody didn't write a proper synopsis. Of course, that can be inadequate or misleading as well.