For those who aren't very familiar with TFS, you may come across a TFS repository whose directories are just Folders, not branches.
In this case, the command git tfs list-remote-branches tfs-url will return the result No TFS branches were found!. Similarly, git tfs clone will not work.
To fix this, open 'Source Control Explorer'. For each folder corresponding to a branch, right click on your source folder and select 'Branching and Merging' > 'Convert to branch'.