What meta tags for adsense?
Meta Tags is used for our blog or site that relevance with Search Engine uses for searching relevance articel.
Meta Tags is :

Meta Keywords: Create your web page with Meta keywords. If there is NO CONTENT on your webpage, the Adsense Media bot will pick-up the Meta Tags, and show ads according to that.

Meta Description: the description meta tag makes it quite important, as it has direct impact over the CTR of your link in the SERPs that leads to your website.

So, make your meta tags is relevance with your articel blog or site.