My bitter experience with Metatags

All my friends told me that by adding Meta tags my site would improve much further. So I added some Metatags from Metatag generators.

But when I was hoping that my site would improve. I found that in the content analysis by Google in webmasters there has been some metatag issues .

Google has found duplicate Metatags in my website and then Google did not index it for some time. But not until I removed the Metatags.