<p dir="auto">There should be a clear mention if the tooltip (and also for other components) can be activated just by including the corresponding css attribute on the element and including the v3 js file, or it does need to be called from a js file of the page.</p>
<p dir="auto">The v2.3.2 docs had the following notice, which is missing from the new docs yet is still applicable AFAICT:</p>
<blockquote>
<p dir="auto">For performance reasons, the tooltip and popover data-apis are opt in, meaning you must initialize them yourself.</p>
</blockquote>