Which inductive schemes can encode the following Agda definition?
No scheme that I know of directly encodes that type. Sometimes it's called a "nested" inductive definition. The complication here is that Maybe and List are type constructors which are external to the signature, and we have to formalize strict positivity for external type operators in general, if we want to allow such definitions. 

In other words, the consistency of A depends on the definition on Maybe and List. Some external type operators are not positive, as in:

data Neg (A : Set) : Set where
  neg : (A -&gt; Bool) -&gt; Neg A

data B : Set where
  b : Neg B -&gt; B


Agda does look into all the external definitions and tries to determine the variance of type parameters. While I don't know a reference for a direct formal specification of this, an easy way to reformulate nested definitions as non-nested is to include the external type operators into a mutual inductive signature. For example:

data A : Set 
data ListA : Set
data MaybeListA : Set

data A where
  a : MaybeListA -&gt; A

data ListA where
  nil : ListA
  cons : A -&gt; ListA -&gt; ListA

data MaybeListA where
  nothing : MaybeListA
  just : ListA -&gt; MaybeListA


This is an ordinary mutual inductive type, which is covered (modulo cosmetic details) by Dybjer's inductive families.