Haven’t fully explored this but the documentation for wp_list_categories is at https://codex.www.ads-software.com/Template_Tags/wp_list_categories#Display_or_Hide_the_List_Heading
About 3/4 down the page their is the description of the Parameter:
use_desc_for_title
(boolean) Sets whether a category’s description is inserted into the title attribute of the links created (i.e. Category Description” href=”…). The default is true (category descriptions will be inserted). Valid values:
* 1 (true) – default
* 0 (false)
Is this what you’re looking for?
