more substantial cleanup of Tool vs. ToolDef crap

llama_stack/models/llama/datatypes.py

@@ -37,14 +37,7 @@ RecursiveType = Primitive | list[Primitive] | dict[str, Primitive]
 class ToolCall(BaseModel):
     call_id: str
     tool_name: BuiltinTool | str
-    # Plan is to deprecate the Dict in favor of a JSON string
-    # that is parsed on the client side instead of trying to manage
-    # the recursive type here.
-    # Making this a union so that client side can start prepping for this change.
-    # Eventually, we will remove both the Dict and arguments_json field,
-    # and arguments will just be a str
-    arguments: str | dict[str, RecursiveType]
-    arguments_json: str | None = None
+    arguments: str
 
     @field_validator("tool_name", mode="before")
     @classmethod

llama_stack/models/llama/llama3/chat_format.py

@@ -232,8 +232,7 @@ class ChatFormat:
                 ToolCall(
                     call_id=call_id,
                     tool_name=tool_name,
-                    arguments=tool_arguments,
-                    arguments_json=json.dumps(tool_arguments),
+                    arguments=json.dumps(tool_arguments),
                 )
             )
             content = ""

llama_stack/models/llama/llama4/chat_format.py

@@ -298,8 +298,7 @@ class ChatFormat:
                 ToolCall(
                     call_id=call_id,
                     tool_name=tool_name,
-                    arguments=tool_arguments,
-                    arguments_json=json.dumps(tool_arguments),
+                    arguments=json.dumps(tool_arguments),
                 )
             )
             content = ""