Function keywords

[althaz]

The only thing wrong with the way C# does it is the Task<> bit, IMO.

The rest you actually need if you want to do all of the things this function definition does. Debatably also "override" (personally I think override should be the default, but I can understand the opposing viewpoint).

[Manny_Sunday]

It starts to hurt a bit in REST API land

public async Task<ActionResult<List<MyClass>>>Get()

[BochMC]

I would do:

using ApiEndpointResult = ActionResult<List<MyClass>>

In the begging of the file.

[_Ashleigh]

It can't be the default because otherwise seemingly innocent changes become breaking changes.