The template name is MySpace and the first argument is the name of the MySpace account. This can be found in the page's URL: if the URL is http://www.myspace.com/example, the account name is example.
The External links guideline recommends avoiding links to MySpace unless the MySpace page is an official page "controlled by the subject (organization or individual person) of the Wikipedia article".
In this example, the MySpace user account is tom and the description in the link is Tom Anderson
In this example, the MySpace user account is 8857543 and the description in the link is Jennifer Aniston