How can I list all Twig functions and filters with their description?
https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Template%21TwigExtension.php/class/TwigExtension/8 Twig functions have no descriptions. You can run getCallable on a twig function/filter object and then do $reflection = new \ReflectionFunction($callable); $doxygen = $reflection-&gt;getDocComment() to get the doxygen which is the closest to "description".