Acting on the Outside World: Read and Write Tools and Reversibility

What happens if Desk looks up an order twice? A few hundred tokens are wasted, and nobody ever knows. What happens if Desk refunds an order twice? The store loses money, and someone must now ask a customer to return it.

To the harness, the two calls look almost identical: a name, some inputs, and a result. Because their consequences differ so much, a careful tool set marks each tool as a read or a write.

Reads and Writes

**A read tool obtains information and changes nothing, and a write tool changes something outside the agent