Enable to customize the internal runner for an agent as tool

[alonhar]

Currently the asTool() helper on Agent only supports toolName, toolDescription, and customOutputExtractor.
However, the underlying runner.run() already supports a maxTurn parameter, which controls the maximum number of turns for the run.

We need to allow users of asTool() to configure this value directly.

Current code (simplified)

asTool(options: {
  toolName?: string;
  toolDescription?: string;
  customOutputExtractor?: (
    output: RunResult<TContext, Agent<TContext, any>>,
  ) => string | Promise<string>;
}): FunctionTool {
  const { toolName, toolDescription, customOutputExtractor } = options;
  return tool({
    name: toolName ?? toFunctionToolName(this.name),
    description: toolDescription ?? '',
    ...
    execute: async (data, context) => {
      const runner = new Runner();
      const result = await runner.run(this, data.input, {
        context: context?.context,
      });
      ...
    },
  });
}

Requested change

Add a new maxTurn?: number option to the asTool() options.

Pass it through to runner.run().

Proposed signature:

asTool(options: {
  toolName?: string;
  toolDescription?: string;
  maxTurn?: number;
  customOutputExtractor?: (
    output: RunResult<TContext, Agent<TContext, any>>,
  ) => string | Promise<string>;
}): FunctionTool


Update the runner.run call:

const result = await runner.run(this, data.input, {
  context: context?.context,
  maxTurn,
});

This ensures that agents wrapped as tools can fully leverage the maxTurn functionality already available in runner.run(), enabling better control over multi-turn execution directly from the tool API.

What do you think? (I can open PR)

[seratch]

Thanks for writing in. I think that developers may want to pass not only maxTurn but also the whole runConfig for customizing the Runner instance, which would be executed within the converted function tool. I will look into this with fresh eyes tomorrow.