All on-page SEO settings can be found in the SEO Tab of the Page Edit screen.
Search Result Title & Description
To set the Page's <title> and <meta type="description"> tags, which show up in Search Engine Listings, you set the Override Title and Override Description values in the Google tab within the SEO tab on the Page Edit screen.
From the Pages tab, click on the Page who's Search Engine values you'd like to change.
Click on the SEO tab.
If not already active, click on the Google tab.
Set the Override Title and Override Description values.
Use the preview below to see how you page will be displayed in Google listings.