---
url: 'https://adk.nht.io/api/@nhtio/adk/exceptions/variables/E_INVALID_TOOL_ARGS.md'
description: >-
  Thrown synchronously when {@link @nhtio/adk!Tool.validate} is called with
  arguments that fail the tool's input schema.
---

# Variable: E\_INVALID\_TOOL\_ARGS

```ts
const E_INVALID_TOOL_ARGS: CreatedException<[]>;
```

Defined in: [lib/exceptions/runtime.ts:396](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/exceptions/runtime.ts#L396)

Thrown synchronously when [@nhtio/adk!Tool.validate](../../forge/classes/Tool.md#validate) is called with arguments that fail the tool's
input schema.

## Remarks

Not fatal — an arg validation failure in the tool call loop is a caller mistake that can be
surfaced as an error response. The tool handler is NOT called when this is thrown.