VMware Tools is a suite of utilities that you install in the operating system of a virtual machine.
VMware Tools enhances the performance of a virtual machine and makes possible many of the ease-of-use features in VMware products.
Although the guest operating system can run without VMware Tools, many VMware features are only available after you install VMware Tools. For example, if you do not have VMware Tools installed on your virtual machine, you cannot get heartbeat information from guest operating systems and you also cannot use the shutdown or restart options from the toolbar. You can only use the power options and you must shut down your guest operating systems from each virtual machine console. You cannot use VMware Tools for connecting and disconnecting virtual devices, and shrinking virtual disks.
VMware highly recomments that you always run the latest version of VMware Tools. You can configure your virtual machine to automatically check for and apply VMware Tools upgrades each time you power on your virtual machines. For information about enabling automatic upgrade of VMware Tools on your virtual machines, see vSphere Virtual Machine Administration.