Function metadata available in middleware/FunctionContext

### Description

Hello, can I access custom metadata about a function method in middleware? For example, I may want middleware to run on most functions but make an exception for some. For this, I was thinking of adding an attribute to the function method and reading this in the middleware (or “UseWhen”). However I can’t see how this is possible. Are there any other approaches? I can’t base it on trigger type or input type.

Start with the middleware, FunctionContext, and UseWhen entry points named in the issue, then trace how function-method information reaches middleware. Done means the project has a clearly supported way to inspect custom function metadata for middleware decisions, with the behavior and limitations documented.

Written by the indexing model from the issue text.