# Agent Builder

> The no-code tool inside Microsoft 365 Copilot that packages a repeatable task into your own agent, with written instructions and chosen knowledge sources.

**Category:** Copilot

**Agent Builder turns a task you keep re-explaining into a named assistant.** It creates what Microsoft calls a **declarative agent**: a custom version of Copilot that follows your instructions and reads only the knowledge sources you picked, such as files, SharePoint sites, Teams chats or public web pages. You describe the job in plain language or fill in the fields yourself, then test it on the Try it tab.

Unlike a Claude [skill](/glossary#skill), which fires quietly when your wording matches, an agent is its own destination that you **open on purpose**. Every new agent starts private. You can share it with colleagues as Can chat or Can edit, or list it in your organisation's Agent Store. Sharing never overrides anyone's own permissions.

## At work

A sales team lead builds a "QBR Summariser" agent that checks every account review against the team template, then shares it with three account managers as Can chat.

## Often confused with

[Copilot Studio](/glossary#copilot-studio). Agent Builder is the lightweight, no-code builder inside Copilot for one job done your way; Copilot Studio is the fuller platform for agents with flows, triggers and actions.

## Related terms

- Agent
- Copilot Studio
- Knowledge source
- Skill

## See it in a lesson

[Agent Builder](/en/learn/copilot/working-smart/agent-builder)

## Further reading

- [Build agents in Agent Builder (Microsoft Learn)](https://learn.microsoft.com/en-us/microsoft-365/copilot/extensibility/agent-builder-build-agents): Microsoft's step-by-step guide to creating an agent.
- [Share and manage agents built in Agent Builder (Microsoft Learn)](https://learn.microsoft.com/en-us/microsoft-365/copilot/extensibility/agent-builder-share-manage-agents): Sharing roles, the Agent Store, and managing the agents you built.
- [Build your own agent with Microsoft Copilot (Microsoft Support)](https://support.microsoft.com/en-us/microsoft-365-copilot/build-your-own-agent-with-microsoft-365-copilot): Microsoft's end-user introduction to building your own agent.

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Last updated: 14/10/2026  
Source: Rollo Academy glossary