I\'m having trouble getting TFPT.exe to work at all, even after trying to refresh the cached workspace settings per the usual advice on the internet. See below for a log repres
As long as you are inside the working directory, tfpt annotate should work. If you are getting the message "Unable to determine the workspace" then it is a caching issue.
If, as you said, you ran tf workspaces /s:serverURL and it still doesn't resolve I would try creating a new workspace and testing it out there. If that works then something wrong with the workspace obviously and I would just delete it and use the new one. If both fail then of course there is a bigger problem but that is how I would approach it.