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# AI Tool
Define a tool that can be invoked by AI Generate.
## Where to Find It
In the Flow Editor, look in the left palette under **AI Gateway**, then drag **Tool** onto your canvas.
AI Tool configuration with Tool ID, Description, and Schema.
## What It Does
The Tool node is the entry point for tool execution when the model decides to call a tool. When invoked, it emits a copy of the AI Generate message with the tool parameters in `msg.payload`.
## Configuration
1. **Name** (optional) - Provide a friendly label for the node.
2. **Tool ID** (required) - The unique identifier the model calls. Tool IDs must be unique within the tools selected by the same AI Generate node and can include letters, numbers, `_`, and `-`.
3. **Description** (optional) - Describe what the tool does to help the model choose it.
4. **Input Schema** (required) - The JSON Schema for tool parameters.
* Use the editor for static schema definitions.
* Use a `msg` reference when you want the schema sourced dynamically from the AI Generate message.
## Outputs
When the model invokes the tool, the node emits a message with:
* `msg.payload` set to the tool parameters
* the rest of the original AI Generate message preserved for context
Use downstream nodes to implement the tool behavior, then finish the tool path with [AI Tool Response](/documentation-and-resources/components-and-data/flows/node-reference/ai-gateway/ai-tool-response.md) to send the result back to AI Generate.
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