Tools
A tool is an action the agent can take mid-conversation: tag the conversation, look up an order in your own system, give up and fetch a person.

Built-in tools
Custom tools
A custom tool calls your own API, so the agent can answer questions only your systems know: where an order is, whether a booking exists, what a customer’s balance is.
Tools are defined once at the account level and granted to individual agents, so the same tool can serve several agents without being rebuilt.

Testing
Run a tool from the editor and see what comes back, before an agent uses it on a real customer.