# HOOK_SIGNATURE

A hook takes the wrong arguments, or is not a plain method.

## What happened

A hook has to be a plain method that takes the arguments Forge passes it. One written as a static method, a class method, an async function, or with other arguments is refused.

## What to do

Write the hook as a plain `def` inside the class with the arguments the message names.

## Example

```text
strategy.py, line 22: `size` must be a plain method, without @staticmethod or @classmethod [HOOK_SIGNATURE]
```

The wording of the message depends on your file, and the code does not. An error stops the file from loading.