Normalize common LLM output errors

libs/python/agent/agent/agent.py

@@ -29,6 +29,7 @@ from .callbacks import (
     TrajectorySaverCallback, 
     BudgetManagerCallback,
     TelemetryCallback,
+    OperatorValidatorCallback
 )
 from .computers import (
     AsyncComputerHandler,
@@ -201,6 +202,9 @@ class ComputerAgent:
 
         # == Add built-in callbacks ==
 
+        # Prepend operator validator callback
+        self.callbacks.insert(0, OperatorValidatorCallback())
+
         # Add telemetry callback if telemetry_enabled is set
         if self.telemetry_enabled:
             if isinstance(self.telemetry_enabled, bool):

libs/python/agent/agent/callbacks/__init__.py

@@ -8,6 +8,7 @@ from .logging import LoggingCallback
 from .trajectory_saver import TrajectorySaverCallback
 from .budget_manager import BudgetManagerCallback
 from .telemetry import TelemetryCallback
+from .operator_validator import OperatorValidatorCallback
 
 __all__ = [
     "AsyncCallbackHandler",
@@ -16,4 +17,5 @@ __all__ = [
     "TrajectorySaverCallback",
     "BudgetManagerCallback",
     "TelemetryCallback",
+    "OperatorValidatorCallback",
 ]