优化文档。

docs/add_effects.md

@@ -151,6 +151,8 @@ curl -X POST https://capcut-mate.jcaigc.cn/openapi/capcut-mate/v1/add_effects \
 4. **Time Overlap**: Multiple effects can be applied to the same time period
 5. **Effect Priority**: Effects are applied in the order they appear in the array
 6. **Performance**: Complex effects may affect video processing performance
+7. **Supported Effects**: System currently supports transition effects like "Fade In", "Fade Out", color filters, etc.
+8. **Preview Limitation**: Effects may not be visible in preview but will be applied during final video generation
 
 ## Workflow
 

docs/add_videos.md

@@ -89,7 +89,7 @@ Batch add video materials to existing drafts. This interface is a powerful video
 
 #### Mask Types
 
-Supported mask types:
+Supported mask types (all optional, default is no mask):
 - `circle` - Circular mask effect
 - `heart` - Heart-shaped mask
 - `star` - Star-shaped mask

docs/create_draft.md

@@ -1,5 +1,8 @@
 # CREATE_DRAFT API Documentation
 
+### 🌐 Language Switch
+[中文版](./create_draft.zh.md) | [English](./create_draft.md)
+
 ## Interface Information
 
 ```
@@ -159,5 +162,4 @@ curl -X POST https://capcut-mate.jcaigc.cn/openapi/capcut-mate/v1/create_draft \
 
 </div>
 
-### Language Switch
-[中文版](./create_draft.zh.md) | [English](./create_draft.md)
+---