I don't think hiding keywords or descriptions would be a problem while you put related keywords to your page and don't spam. I use this "trick" on my websites as well, i put the descriptions for each page between <h1></h1> tags and hide them with CSS. It seems to help on serps.
Anyway, even if you make the text invisiable using css, google bot think it is visiable, google will of course index the text and page.