For me and my add-on that returns the add-on description in .description["en-US"] as “cooked” HTML. Even after I have converted my add-on description on AMO to markdown.
Any chances to get back the “raw” markdown maintained on AMO with that or some other API?
I believe that the rendered HTML returned by the API is identical to what AMO uses to display the description in your add-on’s listing. If you’d like the raw markdown, your best bet might be to open a feature request on https://github.com/mozilla/addons/issues.