How to add description tag

How to add description tag
Hello,
I have an xml file that loads the pictures, but I want to add a description tag for each picture. Below is the xml file for this. Can anyone help me add a description tag that would work?
Thanks,
Tseyigai

<?xml version="1.0" encoding="UTF-8"?>
<galleries>

<!--
**    Please read this information to learn how to add more galleries to your website.
**   
**    Here are all the galleries that you can use for the website pages. Each gallery has
**    an index or ID. With the help of index the gallery can be connected with the definite
**    website page with gallery type. Also this page must have galleryID which should be equal
**    to the gallery index in this file.
**
**    Each gallery consists of the list of images. Each image has and url parameter and also
**    width and height parameters that define dimensions of the box for the image.
**
**    It is recommended to use an XML editor to make changes to this file because it’s less
**    possible to make an error in the markup which can cause a not working website.

**    The recommended size for image_icon=333x333 px.
-->
<gallery id="1" name="nature">
<image image_icon="22598_nature_icon_15.jpg" image="22598_nature_b_15.jpg"/>

<image image_icon="22598_nature_icon_14.jpg" image="22598_nature_b_14.jpg"/>
<image image_icon="22598_nature_icon_13.jpg" image="22598_nature_b_13.jpg"/>
<image image_icon="22598_nature_icon_12.jpg" image="22598_nature_b_12.jpg"/>
<image image_icon="22598_nature_icon_11.jpg" image="22598_nature_b_11.jpg"/>
<image image_icon="22598_nature_icon_10.jpg" image="22598_nature_b_10.jpg"/>
<image image_icon="22598_nature_icon_1.jpg" image="22598_nature_b_1.jpg"/>
<image image_icon="22598_nature_icon_2.jpg" image="22598_nature_b_2.jpg"/>
<image image_icon="22598_nature_icon_3.jpg" image="22598_nature_b_3.jpg"/>
<image image_icon="22598_nature_icon_4.jpg" image="22598_nature_b_4.jpg"/>
<image image_icon="22598_nature_icon_5.jpg" image="22598_nature_b_5.jpg"/>
<image image_icon="22598_nature_icon_6.jpg" image="22598_nature_b_6.jpg"/>
<image image_icon="22598_nature_icon_7.jpg" image="22598_nature_b_7.jpg"/>
<image image_icon="22598_nature_icon_8.jpg" image="22598_nature_b_8.jpg"/>
<image image_icon="22598_nature_icon_9.jpg" image="22598_nature_b_9.jpg"/>

</gallery>
</galleries>