You need to install Team Explorer, it's best to install the version of Team Explorer that matches the version of TFS you are using e.g. if you're using TFS 2010 then install Team Explorer 2010.
I'm in a virtual machine, and am trying to keep my VHD as small as possible, so I find Team Explorer is a really heavyweight solution (300+ MB install). As an alternative, I've had some luck copying a minimal set of EXEs/DLLs from a Team Explorer installation to a clean machine (.NET 4.0 is still required, of course).
I've only tried a handful of operations so far, but this set of files (about 8.5 MB) has been enough to get basic source-control functionality via tf.exe:
(It should go without saying that this is a completely unsupported solution, and it doesn't free you from the normal TFS licensing requirements.)
Depending on the operations you perform, you may find that additional DLLs are required. Fortunately, tf.exe will produce a nice error message telling you exactly which ones are missing.
They will be in my base VM image. I'm going to use it to pull the latest deployment scripts from VC to a temporary local workspace folder when installing a new server.
Following on from the earlier answers above but based on a VS 2019 install ;
I needed to run "tf git permission" commands, and copied the following files from:
C:\Program Files (x86)\Microsoft Visual Studio\2019\TeamExplorer\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer