Most description from SERPs generated from top search engines came from Open Directory Project (ODP) and not from the actual site description. Now, most of the site owners do not like this to happen since most of the descriptions there are outdated or maybe incorrect.
Google now supports META NOODP while MSN gives out their support for the opt out from DMOZ months ago. After adding this code your site header allow 1 day to 3 weeks to see results depending on how often is your site gets crawled.
Tell all robots not to use site description from DMOZ:
<META NAME="ROBOTS" CONTENT="NOODP">
Also works for attribute combination:
<META NAME="ROBOTS" CONTENT="NOODP, NOFOLLOW">
We could specifically direct Googlebot not to use DMOZ descriptions by:
<META NAME="GOOGLEBOT" CONTENT="NOODP">
Or MSN by:
<META Name="msnbot" CONTENT="NOODP">
Note:
SERPs - Search Engine Result Page
