Valve has announced that it will be changing the rules around what developers and publishers can write in Steam store descriptions.
Starting in early September, four sections on the Steam store page will be affected: “About the Game,” “Short Description,” “Any Special Announcements,” and “Awards.” The first new rule is that these sections do not allow links to other websites, including social media pages. This is because the store page already has specific link fields for common social media platforms or websites.
Embedding of images that mimic the Steam store UI or buttons is also not allowed, including images that look like wishlist buttons, game capsules, or prices. Additionally, any images, links or widgets that point to other games on Steam are not allowed. This basically means that developers cannot use store page descriptions to advertise other products on Steam.
Steam has also recently implemented other changes, such as making it easier for players to search for specific games and making game demos more discoverable.