fix: set back some parameters to be non-optional

Author: JackYPCOnline

src/strands/experimental/hooks/events.py

@@ -3,7 +3,7 @@
 This module defines the events that are emitted as Agents run through the lifecycle of a request.
 """
 
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from typing import Any, Optional
 
 from ...hooks import HookEvent
@@ -29,8 +29,8 @@ class BeforeToolInvocationEvent(HookEvent):
     """
 
     selected_tool: Optional[AgentTool] = None
-    tool_use: Optional[ToolUse] = None
-    invocation_state: dict[str, Any] = None
+    tool_use: ToolUse
+    invocation_state: dict[str, Any]
 
     def _can_write(self, name: str) -> bool:
         return name in ["selected_tool", "tool_use"]
@@ -55,10 +55,10 @@ class AfterToolInvocationEvent(HookEvent):
             or an Exception if the tool execution failed.
     """
 
-    selected_tool: Optional[AgentTool] = None
-    tool_use: Optional[ToolUse] = None
-    invocation_state: dict[str, Any] = None
-    result: Optional[ToolResult] = None
+    selected_tool: Optional[AgentTool]=None
+    tool_use: ToolUse
+    invocation_state: dict[str, Any]
+    result: ToolResult
     exception: Optional[Exception] = None
 
     def _can_write(self, name: str) -> bool: