codingnonstop on "Social Sharing Toolkit inside the loop"

Hello!

I'm using social sharing toolkit inside my loop like this:

<?php
$social_sharing_toolkit = new MR_Social_Sharing_Toolkit();
echo $social_sharing_toolkit->create_bookmarks(get_permalink( $post->ID ), get_the_title( $post->ID ), '');
?>

The problem Is that when I'm trying to share the post, preview for sharing shows only the title and the link of the post (which is good because I'm passing that arguments to the function), but not the excerpt from the post.

The texts is taken from meta description of the site. Do you know how to alter the social sharing toolkit, or what argument to pass to the function so the text that shares is related to the post?