Please make sure you have read the Tag Syntax document and understand how tag attribute syntax works.
{% remote_file_content https://raw.githubusercontent.com/apache/struts/master/core/src/site/resources/tags/textarea-description.html %}
{% remote_file_content https://raw.githubusercontent.com/apache/struts/master/core/src/site/resources/tags/textarea-attributes.html %}
<s:textarea label="Comments" name="comments" cols="30" rows="8"/>