You can add meta information to the homepage of your website by navigating to Site Management > Store Configuration, then the Homepage Meta Information section:

The Homepage Meta Title is what displays in the browser tab, and any information entered here will appear after the store name. 

For example:  Store Name | Homepage Meta Title

Google restrict this field to a maximum character count of 60. This figure includes the store name. 

The Homepage Meta Description is not visible to the naked eye on the homepage, but its presence in the background is beneficial to search engines. This field has a maximum character count of 158, and again, this is Google's restriction. 

After adding data to either of these fields, the homepage will update naturally after five minutes.

The meta information also shows on a Google search for your site, as follows:

You will not see changes on Google searches straight away — the changes will not show until Google next index your site. We do not have control over this schedule.

NOTE:  If you use Citrus-Lime's 360 Maintenance package, then the on-page data we have entered there will overwrite any data you include via Cloud MT.