The scope of the journal should be made clear on the About page. For example, the statement that

Minor ‘utility’ packages, including ‘thin’ API clients, are not acceptable.

is hidden all the way down the page on Submitting a paper to JOSS, in our documentation site. We are getting more and more submissions that fall in this category, and authors may not be aware of the eligibility limitations when they submit. We need to make it plainly clear.