The current definition of agent is: "A material entity (either a human being or an aggregate of humans such as an organization) which is active in a process or has the relevant capabilities of intentionality."
We can think of at least one counter example: a service dog.
We therefore propose a slightly broader definition replacing humans with organism in the existing definition i.e. "A material entity (either an organism or an aggregate of organism such as an organization) which is active in a process or has the relevant capabilities of intentionality."