docs: Add docstring for classes and fields that are not supported in Gemini or Vertex API

PiperOrigin-RevId: 822742345

Author: jaycee-li

vertexai/_genai/types.py

@@ -9757,15 +9757,15 @@ class SchemaTablesDatasetMetadata(_common.BaseModel):
     """Represents the metadata schema for multimodal dataset metadata."""
 
     input_config: Optional[SchemaTablesDatasetMetadataInputConfig] = Field(
-        default=None, description=""""""
+        default=None, description="""inputConfig"""
     )
 
 
 class SchemaTablesDatasetMetadataDict(TypedDict, total=False):
     """Represents the metadata schema for multimodal dataset metadata."""
 
     input_config: Optional[SchemaTablesDatasetMetadataInputConfigDict]
-    """"""
+    """inputConfig"""
 
 
 SchemaTablesDatasetMetadataOrDict = Union[