Remove empty comments or add new comments in their place

While reviewing #165, I noticed some empty comments. We should either remove them or insert a comment in place.

Start by reviewing the empty comments identified while reviewing #165, then search the repository for other empty comments. The issue does not name files or specify when to remove a comment versus replace it, so confirm the intended scope and decisions with maintainers; done means the affected comments are no longer empty.

Written by the indexing model from the issue text.