The Meta Description Tag is a part of HTML code that allows you to give a short and concise summary of your web page content.

The Search Engine Results Pages, displays the Title, a user usually reads the description which follows and then decides whether to visit the site or not. A good meta description tag can boost the page rankings on some engines for the targeted search terms. Incase of Flash, Frame or All Image sites that have no content some engines use meta description tag as a site’s summary on their search engine results pages. Hence it is required to make its contents crisp and enticing to the user, thus improving the click through ratio.

Meta Description Tag as it appears in your website’s HTML code:
Some search engines do not give very high prominence to the meta tag description, but then it also is the tag supported by some search engines. Google ignores the meta description tag and instead will automatically generate its own description for this page. Others like Teoma, MSN, HotBot, Yahoo supports it partially.

Guidelines to be followed:

1. Avoid excessive keyword repetition as some of the search engines consider it to be spam.

2. Focus more on the sequence of keywords and place the important terms in the beginning of the meta description tag to form a logical sentence.

3. Make it a point to have an unique meta description tag for each web-page, using the keyword phrases that are relevant to that web page.

4. To avoid truncation by search engines keep your meta description tag to a maximum of 225 characters, if possible limit it to 150 characters.

Its certainly worth the effort to create crisp, compelling keyword rich meta description tags optimization, if it can lead to a better listing in the search engine result pages and higher click through ratio.