If you take your top key word search engine placement within Google and look at your website's description, you will notice something similar with other websites, the descriptions match those taken from Alexa.com!!!
Take a peek for yourself.
1 - Search for your top key word in Google (usually the first key phrase within your title tag).
2 - Now copy & paste this description in a note pad or word doc.
3 - Once you have this, go to: www.alexa.com
4 - Type in your "url" in the address bar
5 - Look at the description from Google and the description from Alexa, they should be an exact match.
NOTE: If you do not have a description in Alexa, Google will come up with its own version but in reality, wouldn't you want to be in control of your website's description within the SERP's?
Not having a description in Alexa - Could it directly affect your Google search engine results?
ABSOLUTELY ! ! !
I would suggest looking at your description in Alexa to make sure that it directly targets your top key phrase that you want performing well within Google.
Your Alexa description could very well determine better SERPS within Google! Google feeds results into Alexa which in turn updates information on website ranking. They are partnered up, why wouldn't they use each others results?!
Alexa's Description is the "text book" definition:
I don't blame Google for wanting to use these descriptions. Most descriptions in Alexa are the "text book version" of your company's description and are usually well written, and well thought out. This would give Google an advantage so that they can spend less time on delivering quality descriptions and more time delivering better results within their searches.
I really like this idea because if this were true across the board, Google would be giving the individual website owner more freedom to write a proper description for their SERPS without using it to spam or create false information. Again, it would have to be approved by Alexa's team anyways, they probably wouldn't allow key word stuffing for their site as it is.