Add VisionService docstrings

src/pipecat/services/vision_service.py

@@ -4,6 +4,13 @@
 # SPDX-License-Identifier: BSD 2-Clause License
 #
 
+"""Vision service implementation.
+
+Provides base classes and implementations for computer vision services that can
+analyze images and generate textual descriptions or answers to questions about
+visual content.
+"""
+
 from abc import abstractmethod
 from typing import AsyncGenerator
 
@@ -13,7 +20,15 @@ from pipecat.services.ai_service import AIService
 
 
 class VisionService(AIService):
-    """VisionService is a base class for vision services."""
+    """Base class for vision services.
+
+    Provides common functionality for vision services that process images and
+    generate textual responses. Handles image frame processing and integrates
+    with the AI service infrastructure for metrics and lifecycle management.
+
+    Args:
+        **kwargs: Additional arguments passed to the parent AIService.
+    """
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
@@ -21,9 +36,31 @@ class VisionService(AIService):
 
     @abstractmethod
     async def run_vision(self, frame: VisionImageRawFrame) -> AsyncGenerator[Frame, None]:
+        """Process a vision image frame and generate results.
+
+        This method must be implemented by subclasses to provide actual computer
+        vision functionality such as image description, object detection, or
+        visual question answering.
+
+        Args:
+            frame: The vision image frame to process, containing image data.
+
+        Yields:
+            Frame: Frames containing the vision analysis results, typically TextFrame
+            objects with descriptions or answers.
+        """
         pass
 
     async def process_frame(self, frame: Frame, direction: FrameDirection):
+        """Process frames, handling vision image frames for analysis.
+
+        Automatically processes VisionImageRawFrame objects by calling run_vision
+        and handles metrics tracking. Other frames are passed through unchanged.
+
+        Args:
+            frame: The frame to process.
+            direction: The direction of frame processing.
+        """
         await super().process_frame(frame, direction)
 
         if isinstance(frame, VisionImageRawFrame):