Figure out whether and where MediaWiki API providess what you want is difficult. T75952 mentions discovering the message list and the interwiki list, but this assumes the developer even knows these terms, and the strings "interwiki" and "message" appear all over the help.
=== Generated API help ===
- In the action list promote action=query "If you're trying to get information about a page, you probably will use [[ https://meta.wikimedia.org/w/api.php?action=help&modules=query&recursivesubmodules=1#query | a submodule of action=query ]]".
- Generated API help could use a TOC and/or collapsible sections, especially with the sprawling single-page `recursivesubmodules=1` mode.
- either change the action and submodule headings (e.g. "prop=extlinks (el)" to be more informative with a blurb, or when collapsed continue to show the description underneath.
- The possible action, prop, list, and meta values display as a long comma-separated list the same as any other parameter value. Instead they could show a blurb/description of what they do, appear as a bulleted list, etc.
- Specialized search of the generated API help
=== ApiSandbox ===
Here all you have is dropdown lists for action and query submodule. It needs ways to explore and search the descriptions of API actions and submodules.
=== on-wiki ===
- @spage added a new section to the API Faq [[ https://www.mediawiki.org/wiki/API:FAQ#figure_out_what_action_or_submodule_to_call.3F | (How do I) figure out what action or submodule to call? ]].