VMware tools used be part of the ESX Classic. You could open a console to your VM and go through the menu and select Install VMware tools. This would mount an iso in the background to the CD drive of the VM. Provided there is one on the VM and by default there is. You could then install the version of the tools specific to the host the VM is operating on.

With the advent of ESXi and AutoDeploy the tools will not necessarily be available on the ESX server.

In my environment we use AutoDeploy. Part of the image building we do not include the VIB for VMware Tools. This makes the AutoDeploy image smaller. Smaller means faster deployment time which means faster Host boot time.
The downside to this it is harder for our compatriots in the operating system teams to get access to the latest or correct version of the tools.

VMware have a site for all the VMware tools back to some versions of 3.5:
https://packages.vmware.com/tools/esx/

The directory structure is pretty self explanatory. If you must have the absolutely latest windows x64 tools version follow:
https://packages.vmware.com/tools/esx/latest/windows/x64/index.html

Or if would like a particular version of the tools, for example x64 Windows for 5.1 Update 1:
https://packages.vmware.com/tools/esx/5.1u1/windows/x64/index.html