Unless the function returns the object it creates, you can't magically get it.
For example:
function makeObject()
{
%obj = new Item();
return %obj;
}
talk(makeObject());
Would print the new object's ID. If you don't return the new object nothing will be echoed.
If you're looking to get an item's ID from serverCmdDropTool you might have to loop through missionCleanup to look for items and find the one that was most recently spawned/belonged to your client.
call .getid(); when so said item spawns
If you're referring to /getID, that doesn't work on item objects.