N8N Update Disables Input Schema in Workflow Tool Node for AI Agents

Hello N8N Team,

I’m one of the contributors to the AI Agent templates in the community. After updating my instance to the latest version, I noticed that the Workflow Tool node for agents has been changed—now you can’t specify input. This change has significant implications because:

1. The same sub-workflow can be reused for several tools, which avoids duplicating dozens of workflows, simplifies maintenance, and adheres to the DRY principle.
2. Without the ability to specify a JSON schema for input, it becomes challenging to build stable agents. While example JSON can be provided in the sub-workflow trigger, it isn’t equivalent to a full JSON schema that supports enum lists, optional parameters, and other detailed definitions. Reliable JSON schema support is essential for developing scalable AI agents. We value N8N for being both low-code and powerful, and removing this option might turn it into another simple automation tool like Zapier.
3. Many existing guides rely on the previous functionality. With the new update, these guides become outdated, leading to confusion among creators.

I propose keeping both options: allow users to specify details in the tool side or use the sub-workflow definition when needed. Below is an example of our approach to agent creation, which allows us to generate new tools with simple GPT prompts and manage them within one workflow.

image912×1584 75.2 KB (
https://community.n8n.io/uploads/default/original/3X/2/4/243d3eb3cd433d651a538724c6703c1dbdbee001.png "image")

image2246×1064 269 KB (
https://community.n8n.io/uploads/default/original/3X/e/e/eec1f446649a49e439428369efdec7295cd7b0c6.png "image")

Now, each Workflow Tool requires its own sub-workflow, without flexible variables for optional parameters.

image886×1588 85.3 KB (
https://community.n8n.io/uploads/default/original/3X/1/2/123d8cc933f59ceb81288a11e1abac74c9a9b41c.png "image")

image894×1450 53.5 KB (
https://community.n8n.io/uploads/default/original/3X/3/b/3bbc5b839c202206a247a8977fb468d64e3875dc.png "image")

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