The title attribute of a link is far more likely to be an accurate description of the content of that link than the link text itself simply because links are almost always used within a context (at least on forums and other online chat mediums). So to build up a picture of the content of a webpage from links to it the emphasis should be placed on the title attribute and the sentence around which the link occurs, not merely the link itself. Therefore there is no need to unnecessarily make formal descriptions part of a link's text.
