apply suggestions

cou/steps/plan.py

@@ -81,9 +81,8 @@ async def generate_plan(analysis_result: Analysis, backup_database: bool) -> Upg
             coro=analysis_result.model.wait_for_idle(
                 # NOTE (rgildein): We need to DEFAULT_TIMEOUT so it's possible to change if
                 # a network is too slow, this could cause an issue.
-                # Since the default timeout is 10 seconds, we need to add 1 second to it to make
-                # sure that timeout is greater than idle_period. At the same time, we are using max
-                # function to ensure lower timeout used it here is always at least 11.
+                # We are using max function to ensure timeout is always at least 11 (1 second
+                # higher than the idle_period to prevent false negative).
                 timeout=max(DEFAULT_TIMEOUT + 1, 11),
                 idle_period=10,
                 raise_on_blocked=True,

cou/utils/juju_utils.py

@@ -464,9 +464,9 @@ async def wait_for_idle(
                             to avoid false positives.
         :type idle_period: int
         :param apps: Applications to wait, defaults to None
-        :type apps: Optional[list[str]], optional
+        :type apps: Optional[list[str]]
         :param raise_on_blocked: If any unit or app going into "blocked" status immediately raises
-                                 WaitForApplicationsTimeout.
+                                 WaitForApplicationsTimeout, defaults to False.
         :type raise_on_blocked: bool
         """