Glossary
Tool
A tool is an external capability an agent can invoke—such as an API, database query, browser, or code runner—via a structured interface.
Tool: A tool is an external capability an agent can invoke—such as an API, database query, browser, or code runner—via a structured interface.
Definition
A tool is an external function an agent can invoke: HTTP APIs, databases, browsers, code runners, ticket systems, or MCP server capabilities.
Design tips
- Strict JSON schemas
- Least-privilege credentials
- Clear error messages models can recover from
- Explicit documentation of side effects
See also
Related reading
Tool Use Pattern
How agents call tools reliably: schemas, selection, error handling, permissions, and verification of side effects.
MCP Explained: Model Context Protocol for Agents
What MCP (Model Context Protocol) is, why it matters for agent tool use, and how to think about servers, clients, and security.