I think it's great to add HelpURLAttribute to the all user-facing components on the VRCSDK.

There is ? button on the inspector to open help page of each component.

This is commonly used in unity-built-in components and recently used by many non-destructive tools such as Modular Avatar, AAO: Avatar Optimizer, lilycal inventory and more.

However, because VRCSDK does not add HelpURLAttribute to their components, clicking the ? button will open invalid page like https://docs-redirects.unity.com/script-VRCAvatarDescriptor?version=2022.3.

I think it's better to fix this by fixing link with HelpURLAttribute.