Inlay Hints
On this page of JetBrains Rider options, you can configure general behavior of inlay hints — configurable editor adornments that improve readability of your code.
Enable Inlay Hints in .NET Languages | Lets you either enable or disable the entire inlay hints functionality in .NET languages (C#, VB.NET, XAML). For Web languages and SQL, you can configure inline hints on the Editor | Inlay Hints | Other Languages page of settings Ctrl+Alt+S. |
Reserve press and hold of the Ctrl key for Push-To-Hint | You may need to clear this checkbox if the press-and-hold of the Ctrl key is already bound to some other actions in your OS or other applications. |
Default visibility | Use the selector to choose how inlay hints in .NET languages should be displayed in the editor (you can override visibility for each language on language-specific pages in this section) : choose Show Always or Never Show to always show or hide hints, or choose Push-to-Hint to hide the hints by default but show them when you press and hold Ctrl. |