After installing facebook all in one extension, QA team was testing facebook send button. Then they found that send button had some funny description. When i checked page source, i found that meta description was using product description which had html formats. If meta description is filled in there will be no such issue but if left empty, it takes description from product.
As core Magento doesn't strip html tags for meta description, let's override it to suit our need:
First create file:
app\code\community\Technooze\Tcatalog\Block\Product\View.php