I couldn't find any official documentation specifying what each parameter to a `sla_miss_callback` callable are. This would be a great addition to know how to properly format the messages sent.
airflow/models/dag.py
params: Optional[Dict] = None,
        access_control: Optional[Dict] = None,
        is_paused_upon_creation: Optional[bool] = None,
        jinja_environment_kwargs: Optional[Dict] = None,
        render_template_as_native_obj: bool = False,
        tags: Optional[List[str]] = None,
    ):
        from airflow.utils.task_group import TaskGroup
        self.user_defined_macros = user_defined_macros
        self.user_defined_filters = user_defined_filters
        self.default_args = copy.deepcopy(default_args or {})
        self.params = params or {}
        
        if 'params' in self.default_args:
            self.params.update(self.default_args['params'])
            del self.default_args['params']
        
        self.params = ParamsDict(self.params)
        if full_filepath:
            warnings.warn(
                "Passing full_filepath to DAG() is deprecated and has no effect",
                DeprecationWarning,
                stacklevel=2,
            )
        validate_key(dag_id)
        self._dag_id = dag_id
        if concurrency and not max_active_tasks:
            
            warnings.warn(
                "The 'concurrency' parameter is deprecated. Please use 'max_active_tasks'.",