My header links doens't have anchor text or image alt, only href - should I use "title"tag?

[Naghirniac]

The header links are only

[john4math]

I remember reading somewhere that the title attributes have no weight for ranking purposes.  If you add a title to a link, it'll add a tool tip showing that text when a user hovers over the link.  So if you think your users would like that, go ahead and add it.

[IM_Learner]

John Barth is absolutely correct. Title attributes add no value to the SEO and acts only as a tool tip. But yes, it could be used for better user experience.