I am not too sure if i understand your question correctly, but here is an attempt to answer
You said you are not using a tag handler, so you don't have a tag-class, so i assume you must be having a <filename>.tag under WEB-INF/tags.
The developer can get the attribute information from the tag file itself
<%@ attribute name="attr" required="true" rtexprvalue="true" %>.
TLD lets you mention the location of your tag file (but thats just the location)
<tag-file> tld element has the following attributes
description
display-name
icon
name
path
example
As you can see there is no place for attribute which is available in the tag tld element.
Further reading
Tag Library Descriptors