How do I show a topic description in category view?

This topic is pinned:

This topic is unpinned (for you) because it’s been read:

We assume that if someone made it to the bottom of that topic they’ve seen it, so the description is no longer necessary on the topic list (and it becomes unpinned). You can disable this functionality by disabling the following settings (admin > settings):

automatically unpin topics

default topics automatic unpin