Definition

What is tool_choice? — Plain-Language AI Definition

An API parameter that controls whether Claude must use a specific tool, can choose any tool, or must respond without tools.

What is tool_choice?

tool_choice is a parameter in the Claude API that controls how the model interacts with available tools.

Key Options

  • auto -- Claude decides whether to use a tool (default)
  • any -- Claude must use at least one tool but picks which
  • tool -- Claude must use a specific named tool
  • none -- Claude cannot use tools

When to Use Each

Use auto for general-purpose agents. Use any when you always want structured output. Use tool with a specific name for forcing data extraction via a particular schema.

Key Takeaway

tool_choice gives you a dial between full model autonomy and strict deterministic tool use.

Learn This in Practice

Move from definition to application with guides and resources that show how this concept appears in real AI workflows.

Get AI Tips Every Week

Get smarter about AI every week — practical tips, prompts, and workflows in your inbox.