The Search Window in the MP editor offers a listing of all available commands.
The search field is typically the best way to find what you are looking for because it automatically filters the list of available command based on what you type in the search window. For example if I want a command to get a relationship from a list of relationships I can start typing "Get i-th re" and the list will filter down to command that include that text:
This window uses a wild-card search automatically so you have the ability to take advantage of that to help find what you want. For example, you can use the start (*) to jump over words you don't know. This allows you to bridge entries like this: "Get * rel* list" and see the following:
Any text entered in the search field or remove from it will immediately update the command listing, so searching is simply a matter of entering a key phrase, editing that phrase and adding wild-card characters as needed until the command shows up in the list. You can then just double-click on it to add it to your MP script.
There are 3 additional buttons in the search section:
Plus. Can be used to expand the categories in the search window
Minus. Can be used to collapse categories in the search window
Two layer Button. This button operates as a toggle and can be used to hide the Analysis section of the MP editor so that more MP commands are visible.