- "Toggle Tooltip display.
-With ARG, turn tooltip mode on if and only if ARG is positive."
+ "Toggle Tooltip mode.
+With ARG, turn Tooltip mode on if and only if ARG is positive.
+When this minor mode is enabled, Emacs displays help text
+in a pop-up window for buttons and menu items that you put the mouse on.
+\(However, if `tooltip-use-echo-area' is non-nil, this and
+all pop-up help appears in the echo area.)
+
+When Tooltip mode is disabled, Emacs displays one line of
+the help text in the echo area, and does not make a pop-up window."