What google takes, sometimes my meta description shown and sometimes products description shown.
I am afraid this has nothing to do with Magento, but with Google itself
Some webmasters and SEOs may consider updating their meta descriptions, but I don’t believe Google would recommend doing so. The snippets are more often dynamically generated based on the user query and content found in both the meta description and the content visible on the page. If Google is going to go with a longer snippet, it likely will pull that content from the page