Generally, menu commands should map to what is visible on screen. For example, if a menu contains an ok button, saying ok will click that button. Similarly, saying trash can will click on any visible trash can. Adding these commands is a manual process that varies from menu to menu, so if a command is missing or not working correctly feel free to create an issue.
All menus with commands can also be navigated with the north, south, east, and west commands to move the mouse to an adjacent clickable section of the active menu. An optional number afterwards will fire the command that many times. For example, if the backpack is open with the mouse over the second item on the first row, saying south two will move the cursor to the second item on the third row. Click and right click will click any button underneath the mouse.
Some menus, like the new game menu, contain text boxes for free form text entry. Dictation is also available - saying title hello world will enter "Hello World", and saying dictate hello world will enter "hello world".