See PHI1998, which identifies issues with the repository "Tags" interface:

• It is significantly different from the "Branches" interface, although both objects are very similar.
• It does not interact correctly with author identities.
• When a tag ref points at a tag object, but the tag object has no message, the UI shows no message at all.
  • Instead, it should probably always show the commit message, and then additionally show the tag message if a tag object with a message exists.
  • When a tag ref points at a tag object, the UI should show the commit hashes for both the tag object and the commit object.