Help with joomla Meta tag

I have been having problem choosing the best meta tag generator for my joomla site, it taking too much time to choose keywords for each article manually because it takes time, what I want is an extension that will generate keyword and description for the body of my article automatically without me looking for keywords each time I write an article, I am loosing a lot of traffic through this because my site will only be listed for keyword that I have chosen for each article while other sites that are wordpress gain high rankings advantages over my website but my contents are more unique than their contents, The extensions that I have been seeing are not working and the good once are premium extensions but I was un able to purchase any because I don’t have PayPal account and they are too expensive for me , Please if any one have a solution to how I can solve this problem or any better extension that I can use to rectify this problem so that my description will be generated automatically, It is not that I have not try other extension but they end up not working and some of them are not even active they just dis-organize my site display on search engines by putting wrong descriptions on articles. Please any help?