# Tool calling

> A language model's ability to use external functions like APIs, search and databases. It's what lets an AI agent take action, not just answer

Источник: https://pachca.com/en/glossary/tool-calling

Tool calling (also called function calling) is how a language model works with external systems. The model gets a list of tools with descriptions and parameters. When a task needs a tool, the model returns a call request instead of text: which function to run and with which arguments. The program runs the call and hands the result back to the model, which decides what to do next.

Examples of tools:

- Send a message or read a thread's history
- Create a task in a tracker
- Read a file in a repo
- Search the web or a knowledge base

Tool calling is what sets an AI agent apart from a chatbot that only replies. MCP makes it easier to connect tools in a common format.

An agent works with Pachca through the API: it sends messages, reads threads and creates tasks and reminders. To help the agent call methods correctly, there's the MCP server, whose tools mirror the API methods, Pachca CLI with command details via --help, Agent Skills and the OpenAPI spec.

Learn more in the Help Center

[Read the article →](https://pachca.com/en/blog/ai-agent-v-korporativnom-messendzhere)

For developers

[Docs on dev.pachca.com →](https://dev.pachca.com/guides/ai-agents/overview?utm_source=pachca.com&utm_medium=glossary&utm_campaign=dev-portal)