It is very common that application needs different format of data, sometime only entity, sometimes with entity type or list of entity. As an example
Business entity
Dept {dept-name,id } has many employee {empl-name, id}.
As entity : {:dept-name "IT"}
List of entity [{:dept-name "IT"}]
Domain type {:dept {:dept-name "IT"}}
List of domain type [{:dept {:dept-name "IT"}}]
Additionally you need to think about namespace qualified key, unqualified key and string conformation. In the end to define spec registry key will be challenging that will be understandable to all team member within project.
spec-model is solution for it. Like UML tools, define business model as data. spec-model will generate spec for it.
Br,
Mamun