Here is an example:
<object name="rope">
<inherit name="editor_object" />
<look type="script">
msg ("The rope leads down a dark hole.")
firsttime {
rope.displayverbs = rope.displayverbs
list add(rope.displayverbs, "Climb")
}
</look>
</object>
The "look" handler for the rope prints out the description. Also, the first time, it adds a "Climb" verb to the display verbs. That will show up both in the right-click menu for the rope and in the right pane.
The assignment of displayverbs to itself is a trick to get rope its own copy of the verbs, as it will have the ones in the base type. Otherwise, you can't add an item to it.