Add `tool_name` to `ToolContext` for generic tool handlers

[illia-botscrew]

Describe the feature

I'm working on a multi-agent AI service and want to use OpenAI Agents SDK to handle multi-agent related logic. In my AI service, function tools should be created via a custom UI admin panel. Function tool configurations will be stored in the external database, and OpenAI Agents SDK's FunctionTools will be built at runtime.

In order to implement it in the way I need, there should be a single on_invoke_tool function used in every dynamically built FunctionTool.

The only thing missing in the current implementation (it is also blocking the implementation) is the ability to know the name of the tool that triggered my generic on_invoke_tool function.

Solution:

Add a new field in the ToolContext: tool_name.

So, the ToolContext class with the new tool_name, most likely, will look like this:

@dataclass
class ToolContext(RunContextWrapper[TContext]):
    """The context of a tool call."""

    tool_name: str <--- new field
    """The name of the tool."""   

    tool_call_id: str = field(default_factory=_assert_must_pass_tool_call_id)
    """The ID of the tool call."""

    @classmethod
    def from_agent_context(
        cls, context: RunContextWrapper[TContext], tool_name: str, tool_call_id: str
    ) -> "ToolContext":
        """
        Create a ToolContext from a RunContextWrapper.
        """
        # Grab the names of the RunContextWrapper's init=True fields
        base_values: dict[str, Any] = {
            f.name: getattr(context, f.name) for f in fields(RunContextWrapper) if f.init
        }
        return cls(tool_name=tool_name, tool_call_id=tool_call_id, **base_values)

With this new field, I will be able to know what tool is "running" now and provide tool_name + args to another service processing the Function tool calls. Without the tool_name, it is impossible to know what tool to process with a generic on_invoke_tool function and multiple FunctionTool classes using a single on_invoke_tool.

I believe this enhancement can be helpful in other projects that need to achieve similar to what I'm trying to achieve.