Running phan (0.12.5) on some extensions I see often:
<error line="" severity="info" message="Call with 2 arg(s) to \Wikimedia\Rdbms\IDatabase::buildLike() which only takes 0 arg(s) defined at ../includes\libs\rdbms\database\IDatabase.php:1138" source="PhanParamTooMany"/>
I would say it needs @param string|LikeMatch,...
I have no idea how to fix this for phan.
Doing things only for a static analyzer is not nice, but the tool is helpful to find other mistakes.
Maybe it needs an own Plugin to declare the varargs on runtime inside phan