# Tool calling — Claude API / OpenAI API Basics

Source: https://www.geekswithgeeks.com/en/llm-apis/llm-apis-06

> Apply Tool calling with clear evidence.

## Understand Tool calling

For **Tool calling**, begin with the problem it solves. Identify the inputs, constraints, and observable outcome before choosing an implementation.

## See the workflow

Use this path while practising **Tool calling**: understand, act, verify, and improve.

![Workflow for Tool calling.](assets/figures/llm-apis/section-2-map.svg) — Figure 2.1 — A repeatable workflow.

## A useful comparison

**Tool calling** is like a route plan: it keeps each step connected to a destination.

Check your reasoning.

**Quiz:** What is the best first step for Tool calling?

- [x] Define the goal and constraints.
- [ ] Copy an unverified example.
- [ ] Skip measurement.

*Answer:* Define the goal and constraints.. A clear goal and constraints make decisions reviewable.