Tested <liferay-ui:icon-help message="Does this work in search container?"/> inside a search container of a view.jsp for a portlet and it displays the question bubble, but no message is displayed when you hover over the icon.
However, when I tried it on another jsp that isn't inside a search container, the icon works just as expected. Every time I mouse over it, the message "Does this work in search container?" will show up.
This is where the code is being used.