diff --git a/README.md b/README.md
index f5a78ab..1853192 100644
--- a/README.md
+++ b/README.md
@@ -430,8 +430,8 @@ When calling a tool:
 | `list_calendars` | List accessible calendars |
 | `get_events` | Retrieve events with time range filtering |
 | `get_event` | Fetch detailed information of a single event by ID |
-| `create_event` | Create events (all-day or timed) with optional Drive file attachments |
-| `modify_event` | Update existing events |
+| `create_event` | Create events (all-day or timed) with optional Drive file attachments and custom reminders |
+| `modify_event` | Update existing events with intelligent reminder handling |
 | `delete_event` | Remove events |
 
 ### 📁 Google Drive ([`drive_tools.py`](gdrive/drive_tools.py))
diff --git a/gcalendar/calendar_tools.py b/gcalendar/calendar_tools.py
index 9b996bd..5bca383 100644
--- a/gcalendar/calendar_tools.py
+++ b/gcalendar/calendar_tools.py
@@ -360,14 +360,19 @@ async def create_event(
 
     # Handle reminders
     if reminders is not None or not use_default_reminders:
+        # If custom reminders are provided, automatically disable default reminders
+        effective_use_default = use_default_reminders and reminders is None
+        
         reminder_data = {
-            "useDefault": use_default_reminders
+            "useDefault": effective_use_default
         }
-        if reminders is not None and not use_default_reminders:
+        if reminders is not None:
             validated_reminders = _parse_reminders_json(reminders, "create_event")
             if validated_reminders:
                 reminder_data["overrides"] = validated_reminders
                 logger.info(f"[create_event] Added {len(validated_reminders)} custom reminders")
+                if use_default_reminders:
+                    logger.info("[create_event] Custom reminders provided - disabling default reminders")
         
         event_body["reminders"] = reminder_data
 
@@ -541,7 +546,12 @@ async def modify_event(
                 logger.warning(f"[modify_event] Could not fetch existing event for reminders: {e}")
                 reminder_data["useDefault"] = True  # Fallback to True if unable to fetch
         
-        if reminders is not None and not reminder_data.get("useDefault", False):
+        # If custom reminders are provided, automatically disable default reminders
+        if reminders is not None:
+            if reminder_data.get("useDefault", False):
+                reminder_data["useDefault"] = False
+                logger.info("[modify_event] Custom reminders provided - disabling default reminders")
+            
             validated_reminders = _parse_reminders_json(reminders, "modify_event")
             if reminders and not validated_reminders:
                 logger.warning("[modify_event] Reminders provided but failed validation. No custom reminders will be set.")