Please try using this PHP snippet instead How to display vendor description in item page? - #2 by yevhen It embeds vendor bio into the vendor block without an extra attribute, it also doesn’t require extra JS/CSS.
You can adjust ‘_order’ to move the embedded description, or replace 'content' => $vendor->display_description(), with 'content' => substr($vendor->get_description(),0,123), to trim the text.
Hope this helps