"Main module", what's that? Never heard of such a thing; mediawiki.org doesn't know either. https://www.mediawiki.org/w/index.php?title=Special%3ASearch&search="main+module"
Given the purpose of this page is mainly to provide the (fantastic!) links à la http://deployment.wikimedia.beta.wmflabs.org/w/api.php?action=help&modules=query , I'd replace the header with "Available actions" or even "Index", to give a nudge in the direction of the path most users will be taking.
Alternatively, if the aim is to describe the content of the section, it should be something like "generic parameters".
Version: unspecified
Severity: enhancement
URL: http://deployment.wikimedia.beta.wmflabs.org/w/api.php