[auto_docstring] _process_kwargs_parameters crashes with AttributeError when   module uses from __future__ import annotations
Author: rpathade
Pull request: no
Labels: name: bug

### System Info

# Bug: `_process_kwargs_parameters` crashes with `AttributeError` when module uses `from __future__ import annotations`

## Description

`@auto_docstring` crashes at import time when applied to a class in a module that uses
`from __future__ import annotations`. The decorator's `_process_kwargs_parameters`
function accesses `kwarg_param.annotation.__args__` directly, but
`from __future__ import annotations` makes all annotations strings at runtime —
strings don't have `__args__`.

## Environment

- `transformers` version: `5.x` (main)
- Python version: 3.12


## Root Cause

`from __future__ import annotations` defers all annotations to strings at runtime.
`kwarg_param.annotation` is `"Optional[IsaacKwargs]"` (a string) instead of the
actual type `Optional[IsaacKwargs]`. Accessing `.__args__` on a string crashes.

The problematic line in `_process_kwargs_parameters`:

```python
# annotation is a string at runtime — crashes here
if kwarg_param.annotation.__args__[0].__name__ not in BASIC_KWARGS_TYPES:
```


## Relation to #45056

[#45056](https://github.com/huggingface/transformers/pull/45056) defers class
docstring generation lazily, which avoids the crash in cases where `cls.__doc__` is
never accessed. However it does not fix the underlying bug — an explicit `cls.__doc__`
access would still crash. This issue is about fixing the root cause directly and is
complementary to #45056.


### Who can help?
 Resolved the issue and validated #45105 

### Information

- [ ] The official example scripts
- [ ] My own modified scripts

### Tasks

- [ ] An officially supported task in the `examples` folder (such as GLUE/SQuAD, ...)
- [ ] My own task or dataset (give details below)

### Reproduction

Any `trust_remote_code=True` model checkpoint whose custom module uses both `from __future__ import annotations` and `@auto_docstring` will trigger this.
Concretely, `PerceptronAI/Isaac-0.1`:

```python
from transformers import AutoTokenizer
AutoTokenizer.from_pretrained("PerceptronAI/Isaac-0.1", trust_remote_code=True)
```


### Expected behavior

Should resolve the string annotation via `typing.get_type_hints()` and generate kwargs documentation normally. If resolution fails, skip gracefully rather than crash.

Comments:
Prefer to leave this on hold until https://github.com/huggingface/transformers/pull/45056 is merged! We can take a look again afterwards

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.

Keeping this un-stale

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.