Any help gratefully recieved on this - how do I get the description to show under my url when someone searches for my site?

To set up my description, I went to 'manage', 'settings', 'SEO', 'Keywords' then wrote my description in the box for 'description'.  When I search for my site the description listed under my site domain name is:  'Home. Website Under Construction. Website Under Construction. Mobile Site.'

Any ideas on how to set up the description that shows underneath url in the list of urls after a search please?