Second try...

Fixed @Jermolene's review comments.
Checked the fix works on tiddlywiki.com and French translation.

plugins/tiddlywiki/menubar/config.tid

@@ -1,6 +1,4 @@
 caption: Menu Bar
-created: 20230519012218346
-modified: 20230712224614730
 tags: $:/tags/ControlPanel/Toolbars
 title: $:/plugins/tiddlywiki/menubar/config
 
@@ -30,10 +28,20 @@ The breakpoint position between narrow and wide screens. Should include CSS unit
 
 !! Contents Tag
 
-The tag for the ~TableOfContents used in the Contents dropdown. Add //caption// and //description// fields to the tag tiddler to change ~TableOfContents' menu label.
+The tag for the ~TableOfContents used in the Contents dropdown.
 
 <$edit-text tiddler="$:/config/plugins/menubar/TableOfContents/Tag" default="" tag="input"/>
 
+Caption of the Contents menu item (stored in the tag's //caption// field):
+
+<$edit-text tiddler={{$:/config/plugins/menubar/TableOfContents/Tag}} field="caption" default="Contents" tag="input" size=50/>
+
+Description of the contents menu item (stored in the tag's //description// field):
+
+<$edit-text tiddler={{$:/config/plugins/menubar/TableOfContents/Tag}} field="description" default="Table of Contents" tag="input" size=50/>
+
+
+
 !! Menu Bar Colours
 
 To change the colour of the menu bar, define the colours `menubar-foreground` and `menubar-background` in the currently selected palette

plugins/tiddlywiki/menubar/items/contents.tid

@@ -1,8 +1,6 @@
-caption: <$text text={{{ [{$:/config/plugins/menubar/TableOfContents/Tag}get[caption]else[Contents]] }}}/>
-created: 20230519010904497
+caption: <$list filter="[{$:/config/plugins/menubar/TableOfContents/Tag}has[caption]]" emptyMessage="Contents"><$transclude $field="caption"/></$list>
 description: <$text text={{{ [{$:/config/plugins/menubar/TableOfContents/Tag}get[description]else[Table of Contents]] }}}/>
 is-dropdown: yes
-modified: 20230712225429073
 tags: $:/tags/MenuBar
 title: $:/plugins/tiddlywiki/menubar/items/contents