A link is essentially a free advertisement on someone else's site pointing back to yours. So when submitting your link information, write it like a well-thought-out advertisement. Here are some guidelines.
1. Give your link text some length -- at least two sentences. If all "link pages" consisted of a short paragraph or two instead of five or six words, these link pages would have "content" and be more valuable. Most webmasters want substance (content) instead of one or two word descriptions. This will also make your listing stand out from the crowd.
2. Pack your link text with your most important keywords. You don't have to "hype" you site. Just pack your description with your most important information. This is called creating a keyword-rich "context".
3. Make sure your "anchor text" includes your most important keyword. The search engines considers this important because the text that is linked is an indicator of the theme of the site being pointed to. Each time a site is pointed to with a link that says "golden retrievers" that site's importance as a "golden retriever" site is reinforced. See the examples at the end of this post.
4. Create more than one version of this link text. A long one should be roughly 200 characters. A short one might be less than 100 characters. Having two or three different versions and lengths of your link text ready to go will make your life a lot easier when it comes to actually placing your links.
5. Mix up your anchor text. If you are doing some serious link work, trying to create hundreds, even thousands of inbound links, don't use the same anchor text all the time. The Search Engines may interpret repetition of the same link patterns as "unnatural" and manipulative. So use different versions of your anchor text and create different link text "contexts".
Concentrate on building keyword-rich contexts in which your subject matter is clearly stated and your links can be clearly associated with the subject matter that is most "relevant" to your site. This is the best way to insure they will create an impact.