Character number in meta description of zipp.sk web site is 243. This is rather above from search engine's meta description criterias. Search engines publish description average till 150 characters. After this number , too many search engines don't take care . You can give give a little short information for text which explains your web site. Try to not only write keywords in meta description part. The meta descriptions which is only hace keywords, can be caused to be banned by search engines.