Problem
API help pages, such as https://www.wikidata.org/w/api.php?action=help&modules=wbsearchentities, do not actually list all the parameters supported by the API. For instance, the uselang parameter is not listed there, since it applies to all of MediaWiki and is not specific to this action. Similarly, the format parameter controls API output format in general and is therefore not listed there either.
As a user, these parameters are very hard to discover: see for instance this question, which I remember asking myself too: https://lists.wikimedia.org/pipermail/wikidata/2020-October/014339.html
The action documentation gives the impression that it lists all the parameters it accepts, which is a problem.
Proposed solution
If there are few such generic parameters, it could be worth including them in all API help pages, perhaps in a different section. If there are too many of them, there should be a prominent link to a page listing them.
For inspiration, consider treating these implied parameters like inherited members of classes in oriented-object programming. For instance, if I look up the documentation of the "QAudioInput" class in Qt, I find by default only the direct members of that class, but there is a prominent link "List of all members, including inherited members" that I can use to see the inherited ones too.