What's wrong with most Description tags? The short answer is almost everything.

Many webmasters don't even take the time to write a Description tag -- or else they write one that is bad, bad, bad!

If you don't write a Description tag, Google will usually pull a couple sentences from different places on your web page. The chance of Google coming up with a compelling Description tag for you is not good to say the least.

The one big thing you want to avoid is having a Description tag that rambles and doesn't make a compelling case for the reader to click and go visit your website.

Another thing you need to watch out for is to make sure you don't go over 150 characters and space. If you do, Google will cut the Description tag off in mid sentence and end it like the Starbucks Description shown below.

By the way, the three little dots are called an ellipses in case you slept through English class the day that was covered (like I did).

Back to your Description tag -- many tests have shown that a Description tag that doesn't end with a clear thought will cut your click through rate. Your Description tag should end like this example:

Also, many tests have shown that unless the keyword phrase that is being searched for appears in your Meta Description tag, Google won't use your Description in their SERPs (Search Engine Results page).

One last point: Remember that nothing is always with Google. The above rules won't guarantee you that the description that shows up on Google's SERP will always be exactly like you want it to be. But the above technique will stack the deck in your favor.

A slight variation in the exact search phrase that people use to find your site could (and will) change the description that Google uses.

Bottom line: You want your Description tag to convert a "looker" into a "clicker." The above techniques will work wonders to help make this happen.