docs(api): add comment explaining post-drop slide (#14069)

api/src/opentrons/protocol_engine/commands/move_labware.py

@@ -116,6 +116,12 @@ async def execute( # noqa: C901
  f"Cannot move {current_labware.loadName} to addressable area {area_name}"
  )
  if fixture_validation.is_gripper_waste_chute(area_name):
+ # When dropping off labware in the waste chute, some bigger pieces
+ # of labware (namely tipracks) can get stuck between a gripper
+ # paddle and the bottom of the waste chute, even after the gripper
+ # has homed all the way to the top of its travel. We add a "post-drop
+ # slide" to dropoffs in the waste chute in order to guarantee that the
+ # labware can drop fully through the chute before the gripper jaws close.
  post_drop_slide_offset = Point(
  x=(current_labware_definition.dimensions.xDimension / 2.0)
  + (GRIPPER_PADDLE_WIDTH / 2.0)