Learning Timeline
Key Insights
Understanding Node Shapes
In n8n, circular nodes are 'Tool Nodes,' while square nodes are regular nodes. AI Agents can only interact with circular nodes as 'tools'.
Known MCP Bug
Currently, there is a bug where the n8n MCP generates regular nodes instead of 'Tool Nodes.' If your nodes appear red or cannot connect to an AI Agent, this is likely the cause.
No-Code Alternative
If you aren't comfortable editing JSON, you can simply delete the regular node and manually search for the 'Tool' version within n8n (e.g., search for 'Airtable Tool'), then re-enter your settings.
Step by Step
How to Manually Fix the 'Tool Node' Bug in n8n JSON
- Select all the nodes in the n8n workflow that you want to fix.
- Press 'Ctrl+C' (Windows) or 'Cmd+C' (Mac) to copy the workflow's JSON code.
- Open an external text editor (such as VS Code, Sublime Text, or Notepad++).
- Paste the JSON code into the text editor.
- Set the editor's language mode to 'JSON' to make the code structure easier to navigate.
- Use the 'Find' function (Ctrl+F) to search for the problematic node (e.g., search for 'airtable').
- Locate the line that shows `"type": "n8n-nodes-base.airtable"`.
- Append the word `Tool` to the end of that node name so it becomes `"type": "n8n-nodes-base.airtableTool"`.
- Repeat the same search and replace steps for other nodes like Notion (`notionTool`) or Google (`googleTool`).
- Copy the entire updated JSON code from your text editor.
- Go back to your n8n dashboard, delete the old nodes, and press 'Ctrl+V' (Paste) to insert the new JSON.
- Click the 'Clean Up' icon (brush icon) to automatically reorganize the node layout.
- Confirm that the node shape has changed from a square (regular node) to a circle (tool node), which can now be connected to an AI Agent.
