Currently, the full tab item description message is displayed as part of the notification when you are not on the app. If you are already on the app or you press the notification without reading the full message, there is no way to read the full message (ios, iphone 12 mini).
I would be good if you could select the item that you wish, for example the two in my screenshot here, and read the full message. It is quite annoying having to ask people what it is for when the message is a little longer than usual. I hope this is clear enough!