# Choose tools and Skills

> Choose system tools, workflow tools, HTTP tools, MCP tools, or Skills for a task.

Source: https://doc.fastgpt.io/en/guide/build/tools/overview

FastGPT provides five capability extension mechanisms: **System Tools (Plugins)**, **Workflow Tools**, **HTTP Tools** (HTTP Tool Sets), **MCP Tools** (MCP Tool Sets), and **Agent Skills**. A Tool is a callable operation with a defined input/output schema; a Skill packages versioned instructions (`SKILL.md`) and supporting scripts for an Agent to load inside a sandbox execution environment.

## Selection Matrix

| Extension Type                | Role                                                                | Configuration Method                                                                                       | Execution Runtime                           | Primary Use Cases and Guide                                                                                                           |
| ----------------------------- | ------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- | ------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| **System Tool / Team Plugin** | Standardized tool packages from the marketplace or local `.pkg`     | Install in Marketplace + configure secrets                                                                 | `fastgpt-plugin` runtime                    | Web search, image generation, IM notifications, database queries; see [Team Plugin Installation](/en/plugin/team-installation)        |
| **Workflow Tool**             | Multi-node canvas workflow wrapped as a reusable function           | Configure the **Plugin start** / **Custom Plugin output** nodes (`pluginInput` / `pluginOutput`) on canvas | FastGPT workflow engine                     | Combine internal retrieval, data cleaning, and API steps; see [Create and Reuse Workflow Tools](/en/guide/build/tools/workflow-tools) |
| **HTTP Tools** (Tool Set)     | Turn external REST APIs into single or batch callable tools         | Import OpenAPI Schema or configure endpoints manually                                                      | Direct HTTP call from FastGPT server        | Connect internal CRM, ERP, or ticketing REST APIs; see [Create and Debug HTTP Tools](/en/guide/build/tools/http_tools)                |
| **MCP Tools** (Tool Set)      | Connect external servers implementing Model Context Protocol        | Configure MCP Address and auth settings                                                                    | External MCP Server (Streamable HTTP / SSE) | Reuse ecosystem or enterprise MCP servers; see [Connect an MCP Tool Set](/en/guide/build/tools/mcp_tools)                             |
| **Agent Skill**               | Versioned package of instructions and scripts for sandbox execution | Author `SKILL.md` + scripts and init hooks                                                                 | Agent VM sandbox (OpenSandbox / Devbox)     | Complex spreadsheet analysis, document generation, multi-command workflows; see [Skill Introduction](/en/guide/build/skill/intro)     |

![Tool call and model interaction loop](https://cdn.jsdelivr.net/gh/labring/fastgpt-img@main/diagrams/tool-call-loop.en.light.svg)

## Workflow tools

Create a [workflow tool](/en/guide/build/tools/workflow-tools), declare caller-supplied parameters and types in **Custom Inputs** on the **Plugin start** node, reference them in the flow, and declare returned values in **Custom Outputs** on the **Custom Plugin output** node. Run it independently with a known input and inspect the output structure. After publishing, select it from another application and verify argument mapping and execution results.

Tool descriptions help models decide when to call an operation; parameter descriptions help them supply values. Describe external write operations clearly and verify permissions and business confirmation requirements before production use.

## Use in applications

* **Chat Agent**: Click **+ Choose** in the left **Tools** section to attach tools for automatic Function Calling; see [Build a Chat Agent](/en/guide/build/chat-agent).
* **Chat Agent V2**: Attach both tool sets and Agent Skills for multi-step autonomous execution inside a virtual machine; see [Chat Agent V2 Settings](/en/guide/build/agentv2/settings).
* **Workflow**: Place tools directly on the canvas as deterministic steps, attach them to a [Tool Call node](/en/guide/build/workflow/nodes/tool), or invoke a tool-enabled Chat Agent V2 from the **Agent** tab of the node panel (legacy workflows also support the standalone [Agent node](/en/guide/build/workflow/nodes/agent)).

See [team tool installation](/en/plugin/team-installation), [system tool development](/en/plugin/system-tool-development), and [Skill integration](/en/guide/build/skill/integration) for the two Agent integration surfaces.