Add tool call arguments in ToolContext for RunHooks

Author: ihower

examples/basic/lifecycle_example.py

@@ -46,15 +46,15 @@ async def on_agent_end(self, context: RunContextWrapper, agent: Agent, output: A
     async def on_tool_start(self, context: RunContextWrapper, agent: Agent, tool: Tool) -> None:
         self.event_counter += 1
         print(
-            f"### {self.event_counter}: Tool {tool.name} started. Usage: {self._usage_to_str(context.usage)}"
+            f"### {self.event_counter}: Tool {tool.name} started. name={context.tool_name}, call_id={context.tool_call_id}, args={context.tool_arguments}. Usage: {self._usage_to_str(context.usage)}"  # type: ignore[attr-defined]
         )
 
     async def on_tool_end(
         self, context: RunContextWrapper, agent: Agent, tool: Tool, result: str
     ) -> None:
         self.event_counter += 1
         print(
-            f"### {self.event_counter}: Tool {tool.name} ended with result {result}. Usage: {self._usage_to_str(context.usage)}"
+            f"### {self.event_counter}: Tool {tool.name} finished. result={result}, name={context.tool_name}, call_id={context.tool_call_id}, args={context.tool_arguments}. Usage: {self._usage_to_str(context.usage)}"  # type: ignore[attr-defined]
         )
 
     async def on_handoff(
@@ -128,19 +128,19 @@ async def main() -> None:
 ### 1: Agent Start Agent started. Usage: 0 requests, 0 input tokens, 0 output tokens, 0 total tokens
 ### 2: LLM started. Usage: 0 requests, 0 input tokens, 0 output tokens, 0 total tokens
 ### 3: LLM ended. Usage: 1 requests, 143 input tokens, 15 output tokens, 158 total tokens
-### 4: Tool random_number started. Usage: 1 requests, 143 input tokens, 15 output tokens, 158 total tokens
-### 5: Tool random_number ended with result 69. Usage: 1 requests, 143 input tokens, 15 output tokens, 158 total tokens
+### 4: Tool random_number started. name=random_number, call_id=call_IujmDZYiM800H0hy7v17VTS0, args={"max":250}. Usage: 1 requests, 143 input tokens, 15 output tokens, 158 total tokens
+### 5: Tool random_number finished. result=107, name=random_number, call_id=call_IujmDZYiM800H0hy7v17VTS0, args={"max":250}. Usage: 1 requests, 143 input tokens, 15 output tokens, 158 total tokens
 ### 6: LLM started. Usage: 1 requests, 143 input tokens, 15 output tokens, 158 total tokens
 ### 7: LLM ended. Usage: 2 requests, 310 input tokens, 29 output tokens, 339 total tokens
 ### 8: Handoff from Start Agent to Multiply Agent. Usage: 2 requests, 310 input tokens, 29 output tokens, 339 total tokens
 ### 9: Agent Multiply Agent started. Usage: 2 requests, 310 input tokens, 29 output tokens, 339 total tokens
 ### 10: LLM started. Usage: 2 requests, 310 input tokens, 29 output tokens, 339 total tokens
 ### 11: LLM ended. Usage: 3 requests, 472 input tokens, 45 output tokens, 517 total tokens
-### 12: Tool multiply_by_two started. Usage: 3 requests, 472 input tokens, 45 output tokens, 517 total tokens
-### 13: Tool multiply_by_two ended with result 138. Usage: 3 requests, 472 input tokens, 45 output tokens, 517 total tokens
+### 12: Tool multiply_by_two started. name=multiply_by_two, call_id=call_KhHvTfsgaosZsfi741QvzgYw, args={"x":107}. Usage: 3 requests, 472 input tokens, 45 output tokens, 517 total tokens
+### 13: Tool multiply_by_two finished. result=214, name=multiply_by_two, call_id=call_KhHvTfsgaosZsfi741QvzgYw, args={"x":107}. Usage: 3 requests, 472 input tokens, 45 output tokens, 517 total tokens
 ### 14: LLM started. Usage: 3 requests, 472 input tokens, 45 output tokens, 517 total tokens
 ### 15: LLM ended. Usage: 4 requests, 660 input tokens, 56 output tokens, 716 total tokens
-### 16: Agent Multiply Agent ended with output number=138. Usage: 4 requests, 660 input tokens, 56 output tokens, 716 total tokens
+### 16: Agent Multiply Agent ended with output number=214. Usage: 4 requests, 660 input tokens, 56 output tokens, 716 total tokens
 Done!
 
 """

src/agents/tool_context.py

@@ -24,6 +24,9 @@ class ToolContext(RunContextWrapper[TContext]):
     tool_call_id: str = field(default_factory=_assert_must_pass_tool_call_id)
     """The ID of the tool call."""
 
+    tool_arguments: Optional[str] = None
+    """The raw arguments string of the tool call."""
+
     @classmethod
     def from_agent_context(
         cls,
@@ -39,4 +42,8 @@ def from_agent_context(
             f.name: getattr(context, f.name) for f in fields(RunContextWrapper) if f.init
         }
         tool_name = tool_call.name if tool_call is not None else _assert_must_pass_tool_name()
-        return cls(tool_name=tool_name, tool_call_id=tool_call_id, **base_values)
+        tool_args = tool_call.arguments if tool_call is not None else None
+
+        return cls(
+            tool_name=tool_name, tool_call_id=tool_call_id, tool_arguments=tool_args, **base_values
+        )