Google Maps API XML Add Marker Description

I’m trying to help my dad out with his real estate website. He wants to have a google map displaying his properties on there. So far I’ve been able to use the Google Map API to make a map and add markers downloaded from an XML source file. The XML file looks like this:

<markers>
<marker lat=“38.679917” lng="-121.315895"/>
<marker lat=“38.708823” lng="-121.389302"/>
<marker lat=“38.663036” lng="-121.277524"/>
</markers>

What I can’t find any info on is how to add a description when the click on the markers using XML. Does anyone know how to do this?

Thanks in advance