If you scroll through an official description and hit a short paragraph about the act's own app, you are looking at a standing block. It tends to appear in the same words under many uploads, which is the first clue that it is not news about the video you just watched. We read it the way we read a footer: useful as a pointer to a place where the act keeps community features, but separate from the upload itself. The block usually mentions things like collecting digital items, joining polls or using community spaces, and then a row of links.
The video and the block are two different things sharing one text box. The block does not tell you anything about the song, the release or what the act is doing next, so please do not read a schedule or a plan into it. Words such as limited or seasonal deserve the same care. Those words describe items inside the app, and they are set by the app's operator, not by the video's release. A description cannot tell you how long an item lasts, how it is earned or what it is worth.
The links are where we would slow down. Download links normally lead to phone stores, and before installing anything we would open the store page and check that the publisher shown is the act's own official one, since look-alike listings exist. Shortened links hide their destination, so read where they lead before you tap, or find the same app by going to the act's official channel and following the link from there. A web shop link is a different case again: it is for purchases, and it is separate from streaming links, so it does not help or hurt how you play the video.
Sign-ups, in-app purchases and votes each have their own terms inside the app, and the description does not state them. That means the price, the rules, any age limits and how a poll is counted are all things you can only confirm on the app's own page or in the act's official notices. We should be honest about the limits here too. Blocks differ between acts, the wording may be a translation that loses detail, and nothing in a description tells you what happens after you open the app. Treat the block as a signpost, and let the official pages do the explaining.