diff --git a/window-tool-bar.el b/window-tool-bar.el
index 81c2ad5..2177217 100644
--- a/window-tool-bar.el
+++ b/window-tool-bar.el
@@ -18,13 +18,20 @@
 
 ;;;###autoload
 (defun window-tool-bar-string ()
+  "Return a (propertized) string for the tool bar.
+
+This is for when you want more customizations than
+`window-tool-bar-mode' provides.  Commonly added to
+`tab-line-format', `header-line-format', or `mode-line-format'"
   (let ((toolbar-menu (cdr (keymap-global-lookup "<tool-bar>"))))
     (mapconcat #'window-tool-bar--keymap-entry-to-string toolbar-menu " ")))
 
 (defun window-tool-bar--keymap-entry-to-string (menu-item)
-  "Convert MENU-ITEM into a (propertized) string representation."
+  "Convert MENU-ITEM into a (propertized) string representation.
+
+MENU-ITEM: Menu item to convert.  See info node (elisp)Tool Bar."
   (pcase menu-item
-    (`(,key menu-item ,name . ,props)
+    (`(,key menu-item ,name . ,_)
      ;; Normal menu item, turn into propertized string button
      (let* ((str (format "[%s]" name))
             (enable-form (plist-get menu-item :enable))
@@ -71,6 +78,7 @@
     (setq tab-line-format nil)))
 
 (defun window-tool-bar--turn-on ()
+  "Internal function called by `global-window-tool-bar-mode'."
   (window-tool-bar-mode 1))
 
 ;;;###autoload