Oh, for those who don't understand the meaning of metadata, I just figured out a simple example. Imagine that web site is a book - same that you would see in a book store or library. Title - is what you see on the cover. Description is the author's intro on first page. Ask yourself, how would you buy a book? You look at the cover and if this is what you want, you take it and read the intro on first page. Is that right?
Well, same with web pages, you should be able to read page title with one look, then if you need more info, you look at description.
I saw many web sites where title exceeded 400 chars, so imagine you saw a book in the shop that has such title. How long would you need to stare at it before you decide to buy it?
Now that you know how books looks, you'll be able to make good web titles
