Find Real Openings

The dispatcher can share a quote now, but the very next thing a customer says is "great, when can you take it?" Watch what happens: with no way to see the calendar, it'll cheerfully offer you "Tuesday at 2" with the same confidence it once invented prices. Maybe Tuesday's booked solid. The agent has no idea.

We fixed pricing with a tool, and we'll fix the calendar the same way. In eve, giving the agent a new ability usually means adding another file to tools/; the framework discovers and wires it for you.

This tool takes no input.

Outcome

The dispatcher offers real open repair slots by calling a check_availability tool, instead of guessing at times.

Hands-on exercise

You've done this shape once, so this is mostly muscle memory now. Create agent/tools/check_availability.ts with the same three pieces: a description, an inputSchema, and an execute.

Looking up open slots needs no arguments, but inputSchema is still required. Use an empty object schema:

inputSchema: z.object({}),

That empty object is the contract. It tells the model that the tool takes no arguments, while still satisfying the required schema.

The calendar lives in agent/lib/shop.ts next to the catalog. Import listOpenSlots and return each open slot as a small object the model can read back to the customer, an id it can quote to a booking tool later, and a human when label like "Tue 10:00am".

Return ids with the labels

Give the model both the slot's id and its human label. The label is what it says to the customer ("Tuesday at 10"); the id is what it'll hand to book_repair in Section 3. Returning both now saves a round-trip later.

Try It

Restart and walk the customer from price to booking:

npx eve dev

you › a basic tune-up sounds good, when can you fit me in?

  ⚙ check_availability  {}
  ↳ [{ slotId: "tue-10", when: "Tue 10:00am" }, { slotId: "wed-09", when: "Wed 9:00am" },
     { slotId: "thu-11", when: "Thu 11:00am" }]

dispatcher › I've got Tuesday at 10, Wednesday at 9, or Thursday at 11 open for a
basic tune-up. Any of those work for you?

These openings came from the shop's calendar. The dispatcher omitted the booked Wednesday 4pm slot because listOpenSlots() never returned it.

The agent only knows what the tool returns

The model can't offer a booked slot because the data never reached it. Instead of prompting it to "avoid taken slots," return only the available ones. The tool's return value defines what the agent knows for that question.

No check_availability in the loop? Run eve info and confirm the tool shows up. If the agent answers without calling it, make the description more specific. Say that the tool lists currently open booking slots so the model knows when to use it.

Done-When

agent/tools/check_availability.ts default-exports defineTool with an empty z.object({}) schema.
eve info lists check_availability.
Asking about scheduling triggers a check_availability call.
The offered times match the open slots in agent/lib/shop.ts, and exclude booked ones.

Solution

agent/tools/check_availability.ts

import { defineTool } from "eve/tools";
import { z } from "zod";
import { listOpenSlots } from "../lib/shop.js";
 
export default defineTool({
  description: "List the repair slots that are currently open for booking.",
  inputSchema: z.object({}),
  async execute() {
    return listOpenSlots().map((s) => ({ slotId: s.id, when: s.label }));
  },
});

Each new ability has its own file, and the filename identifies the ability. Next, the dispatcher needs memory that lasts beyond a single answer.