Python: BaseTool class is not exported in _tools.py

[anguzo]

Description

The BaseTool class is defined in the codebase but is not exported in the module's __all__ list, making it impossible to import directly. While duck typing with ToolProtocol should work, I think this base class should be importable.

Current Behavior

Users cannot import the class:

from agent_framework import BaseTool  # ✗ ImportError or not discoverable

Expected Behavior

Users should be able to import and use the base class:

from agent_framework import BaseTool  # ✓ Should work

Why This Matters

• BaseTool is the recommended base class for creating custom tools
• The documentation and examples show inheriting from BaseTool, but it's not exported

Current all (from tools.py)

__all__ = [
    "FUNCTION_INVOKING_CHAT_CLIENT_MARKER",
    "AIFunction",
    "HostedCodeInterpreterTool",
    "HostedFileSearchTool",
    "HostedMCPSpecificApproval",
    "HostedMCPTool",
    "HostedWebSearchTool",
    "ToolProtocol",
    "ai_function",
    "use_function_invocation",
]

Suggested Fix

Add BaseTool to __all__:

__all__ = [
    "FUNCTION_INVOKING_CHAT_CLIENT_MARKER",
    "AIFunction",
    "BaseTool",  # Add this
    "HostedCodeInterpreterTool",
    # ... rest of exports
]

[eavanvalkenburg]

BaseTool is in fact not advised to be used by other developers just a internal class that we use and might change, so we will not expose it from the public root, Tool support is far too tied into clients to be extended with ease, the ToolProtocol is enough for that purpose.