When thinking about designing social media platforms, we often focus on factors such as usability, functionality, aesthetics, ethics, and so forth. Epistemic considerations have rarely been given the same level of attention in design discussions. This paper aims to rectify this neglect. We begin by arguing that there are epistemic norms that govern environments, including social media environments. Next, we provide a framework for applying these norms to the question of platform design. We then apply this framework to the real-world case of long-form informational content platforms. We argue that many current long-form informational content platforms are epistemically unhealthy. The good news? We provide concrete advice on how to take steps toward improving their health! Specifically, we argue that they should change how they verify and authenticate content creators and how this information is displayed to content consumers. We conclude by connecting this guidance to broader issues about the epistemic health of platforms.