You could also replace <br/> with 
 and add a linefeed-treatment="preserve" attribute to your <fo:block>.
Something like:
<fo:block linefeed-treatment="preserve">This is an example Description.
List item 1
List item 2
List item 3
List item 4</fo:block>
Edit
Some users may need to use \n instead of 
 depending on how they are creating the XML. See Retain the 
 during xml marshalling for more details.