How to create a tool with no parameters?

[imajus]

How do I properly define a tool with no input parameters? The SDK doesn't permit to omit the parameters attribute in the tool definition. I tried to define an empty Zod object as a schema, which is accepted, but the tool is never get called that way.

My use cases is that I need to extract some data from the run context but don't want to pass this data through the LLM inference.

How do I instruct the LLM to call a tool with no parameters accepted?

[seratch]

Hi @imajus, thanks for writing in! I think that's a matter of instructions. You can give even clearer instructions to your agents to let them understand when and how tools should be used:

import { Agent, run, tool } from "@openai/agents";
import { z } from "zod";

const NoParams = z.object({});

type MyContext = {
  name: string;
};

const myTool = tool<typeof NoParams, MyContext>({
  name: "My Useful Tool",
  description: "This tool is useful for people",
  parameters: NoParams,
  execute: async ({}, context) => {
    if (context) {
      return `Hey, ${context.context.name}! You're amazing!`;
    } else {
      return "Hey, you! You're amazing!";
    }
  },
});

const agent = new Agent({
  name: "My Assistant",
  instructions:
    "You are a helpful assistant. When you're asked to do something meaningful, you must use your tools and include the tool outputs in the final output.",
  tools: [myTool],
});

async function main() {
  const result = await run(agent, "Hi, can you say something nice about me?", {
    context: { name: "Kaz" },
  });
  console.log(result.finalOutput);
}

main();

Hope this helps!

[imajus]

I've finally made it work, thank you. The problem was in the tool description. Changing it resolved the issue.

I bet there are many other use cases for this, e.g. generating random numbers or getting current date. So I think that there must be a straightforward documented way to implement tools with no input parameters. Ideally the tool definition should not require the parameters attribute.

[seratch]

Thanks for your feedback! We may update the tools document page to mention your use case too!