---
id: "anthropic-writing-tools-for-agents"
title: "Writing effective tools for AI agents"
creator: "Anthropic"
url: "https://www.anthropic.com/engineering/writing-tools-for-agents"
level: "advanced"
category: "agents"
models: ["any"]
source_date: "2025-09-11"
date_added: "2026-10-18"
---

[Agents and harnesses](/agents/index.md)

# Writing effective tools for AI agents

by Anthropic

[Read the original →](https://www.anthropic.com/engineering/writing-tools-for-agents)

How to design, evaluate and improve the tools an agent calls.

Anthropic discusses shaping tool interfaces and evaluating how agents use them. The emphasis is on testing whether a tool helps accomplish the task rather than merely exposing an API.

Level: [Advanced](/levels/index.md#advanced)
Models: any
Category: [Agents and harnesses](/agents/index.md)
Tags: [tools](/tags/tools/index.md)
Source date: 2025-09-11
Added: 2026-10-18
Last verified: 2026-10-18
Status: ok

Summary in our own words. All rights with the original creator. Correction or removal: DM on X.