If you're talking about dropping a tool:
You can, although you may have to do something with serverCmdDropTool(%client, %slotID)
This is how it works:
messageClient(%client, 'MsgItemPickup', '', int slotID, ItemData toolID, bool isSilent);
Example:
0 - First slot from the client's tool HUD
nameToID(GunItem) - Just send tool IDs, as far as I know if you send names it will not work and still think it's not an object since the client doesn't have datablocks named
true - (Can also just be 1, makes the sound silent, they won't know if they have an item or not)
messageClient(%client, 'MsgItemPickup', '', 0, nameToID(GunItem), true);