# Tools overview

> How an agent takes action and reads live data through MCP.

Source: https://docs.runbear.io/agents/tools/overview

Last updated: 2026-08-26

Tools let an agent do things instead of only describing them: look up a record,
create a ticket, run a query, post to an API. Runbear connects them over
**MCP (Model Context Protocol)**, an open standard for giving agents access to
external systems.

## How a tool call works

When a message needs something the agent does not already know, the agent picks a
tool, calls the connected MCP server, and uses what comes back to answer. This
happens mid-conversation, so the answer reflects the state of the system at that
moment.

Asking "what is the status of RB-1234" makes the agent call the Linear tool, read
the issue, and reply with its current status rather than a remembered one.

## Managed servers and your own

|          | [Managed catalog](/agents/tools/catalog.md) | [Custom MCP](/agents/tools/custom-mcp.md) |
| -------- | ------------------------------------------- | ----------------------------------------- |
| Hosting  | Runbear                                     | You                                       |
| Setup    | Authorize with OAuth                        | Provide a server URL                      |
| Good for | Common SaaS integrations                    | Internal tools and private APIs           |

## Who the agent acts as

A connected tool authorizes one of two ways.

**Per-User** means each member links their own account, and the agent acts with
that member's permissions. Two people asking the same question can get different
answers, which is usually what you want for a CRM or an issue tracker.

**Shared** means one account serves everyone on the agent. Simpler, but every user
of the agent inherits that account's access, so grant it deliberately.

## Tools or knowledge

|         | Tool                                     | [Knowledge](/agents/knowledge/overview.md) |
| ------- | ---------------------------------------- | ------------------------------------------ |
| Source  | A live API call                          | Documents synced ahead of time             |
| Answers | "What is true right now" and "do this"   | "What does our documentation say"          |
| Example | Create a Linear issue, look up a payment | Answer from the refund policy              |

Most agents use both.

## Related

- [Tool catalog](/agents/tools/catalog.md)
- [Custom MCP](/agents/tools/custom-mcp.md)
- [Tool approvals](/administration/tool-approvals.md)