Plone Image description field is used for alt-attribute but not explained

I didn‘t find a hint on a documentation and needed to try myself to find out.

i guess the simplest would be to alter the description text of the Plone Image type‘s description field, so editors know that that text input is also used for the text-alternative of that image.

Or is there a reason to not tell editors where that info is used in addition to listings and summaries?