The toolbar on the Watch window contains the following buttons:

Add Watch

Invokes the Add Watch command to add a new variable to the Watch window. This variable can be selected from any active text window or typed in the Add Watch dialog box.

Clear Window

Removes all variables from the Watch window.

Sort Expressions

Sorts the variables in the Watch window alphabetically by name.

Copy to Trace/Log

Copies the contents of the Watch window to the Trace window. If logging is active, the contents of the Watch window are also copied to the trace log.