[BUG] Can't annotate markdown file

[donatojb]

Describe the bug
The endpoint for annotations crashes when sending a markdown file.

To Reproduce

from axiomatic_mcp.servers.annotations.server import annotate_file_main
md_path = Path('tests/test6/test6_annotations.md')
response = await annotate_file_main(md_path, query='Test')

raises an error

---------------------------------------------------------------------------
HTTPStatusError                           Traceback (most recent call last)
File ~/Donato/Code/AutoVJ/.venv/lib/python3.13/site-packages/axiomatic_mcp/shared/api_client.py:28, in AxiomaticAPIClient._handle_raise_for_status(self, response)
     27 try:
---> 28     response.raise_for_status()
     29 except httpx.HTTPStatusError as e:

File ~/Donato/Code/AutoVJ/.venv/lib/python3.13/site-packages/httpx/_models.py:829, in Response.raise_for_status(self)
    828 message = message.format(self, error_type=error_type)
--> 829 raise HTTPStatusError(message, request=request, response=self)

HTTPStatusError: Server error '500 Internal Server Error' for url 'https://api.axiomatic-ai.com/annotations/'
For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500

The above exception was the direct cause of the following exception:

HTTPStatusError                           Traceback (most recent call last)
File ~/Donato/Code/AutoVJ/.venv/lib/python3.13/site-packages/axiomatic_mcp/servers/annotations/server.py:150, in annotate_file_main(file_path, query)
    148 data = {"query": query}
--> 150 response = await asyncio.to_thread(
    151     AxiomaticAPIClient().post,
    152     "/annotations/",
    153     files=files,
    154     data=data,
    155 )
    157 annotations_response = AnnotationsResponse.model_validate(response)

File /opt/homebrew/Cellar/python@3.13/3.13.7/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/threads.py:25, in to_thread(func, *args, **kwargs)
     24 func_call = functools.partial(ctx.run, func, *args, **kwargs)
---> 25 return await loop.run_in_executor(None, func_call)

File /opt/homebrew/Cellar/python@3.13/3.13.7/Frameworks/Python.framework/Versions/3.13/lib/python3.13/concurrent/futures/thread.py:59, in _WorkItem.run(self)
     58 try:
---> 59     result = self.fn(*self.args, **self.kwargs)
     60 except BaseException as exc:

File ~/Donato/Code/AutoVJ/.venv/lib/python3.13/site-packages/axiomatic_mcp/shared/api_client.py:59, in AxiomaticAPIClient.post(self, endpoint, data, files, params)
     57     response = self.client.post(endpoint, json=data, params=params)
---> 59 self._handle_raise_for_status(response)
     60 return response.json()

File ~/Donato/Code/AutoVJ/.venv/lib/python3.13/site-packages/axiomatic_mcp/shared/api_client.py:32, in AxiomaticAPIClient._handle_raise_for_status(self, response)
     31     error_body = response.text
---> 32     raise httpx.HTTPStatusError(f"{e!s} - Response: {error_body}", request=response.request, response=response) from e
     33 except Exception:

HTTPStatusError: Server error '500 Internal Server Error' for url 'https://api.axiomatic-ai.com/annotations/'
For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500 - Response: {"detail":"Annotation failed: Error annotating source: Only images and PDFs are supported for binary content"}

The above exception was the direct cause of the following exception:

ToolError                                 Traceback (most recent call last)
Cell In[26], line 3
      1 from axiomatic_mcp.servers.annotations.server import annotate_file_main
      2 md_path = Path('tests/test6/test6_annotations.md')
----> 3 response = await annotate_file_main(md_path, query='Test')

File ~/Donato/Code/AutoVJ/.venv/lib/python3.13/site-packages/axiomatic_mcp/servers/annotations/server.py:163, in annotate_file_main(file_path, query)
    158     annotations_text = (
    159         format_annotations(annotations_response.annotations) if annotations_response.annotations else "No annotations found for the given query."
    160     )
    162 except Exception as e:
--> 163     raise ToolError(f"Failed to annotate file: {e!s}") from e
    165 try:
    166     with (file_path.parent / f"{file_path.stem}_annotations.md").open("w", encoding="utf-8") as f:

ToolError: Failed to annotate file: Server error '500 Internal Server Error' for url 'https://api.axiomatic-ai.com/annotations/'
For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500 - Response: {"detail":"Annotation failed: Error annotating source: Only images and PDFs are supported for binary content"}

Expected behavior
The endpoint should return the annotations for the pdf.

Environment (please complete the following information):

• OS: macOS
• Python version: 3.13.7
• Package version: 0.1.15
• MCP client: VSCode