Tool
A tool is an operation an AI application exposes for the model to request, such as searching documents or looking up a record. Its interface defines the information needed to use it.
[Anthropic]In practice · hypothetical example
An order lookup accepts an order number and returns a status.
[Anthropic]A little deeper
Tool descriptions help the model choose an operation and supply its arguments. [Anthropic]
Similar terms, different emphasis
Compare Tool & Agent Skill →Which is an example of a tool?
Sources & editorial notes
Evidence: supported. Primary-source support for this scoped entry; publication approved by the project owner.
- Building effective agents ↗ (opens in new tab)Anthropic · 2024-12-19
Relevant section: What are agents?; Building blocks; Agents; Appendix 2
Last editorial review: 2026-09-13 by project-owner.
First observed in this corpus: Unknown.
Revision history
Revision 2 · Created 2026-09-12 · Updated 2026-09-13
Project owner approved the current content for publication. Existing evidence scope and limitations remain applicable.