You can go to the category where the site is listed and click the Update_URL link at the top right of the page. Bear in mind that some areas have strict rules about what is and isn't allowed to be used as a site title, and that we do not change descriptions to add keywords.
If there is something wrong with either your title or description, we'll change it. If what we've written is correct, but you just don't like it, we'll probably leave it as it is.