Do not use the mixin docstring for the schema (#12675)

src/prefect/_internal/compatibility/deprecated.py

@@ -20,8 +20,10 @@
 
 if HAS_PYDANTIC_V2:
     from pydantic.v1 import BaseModel, Field, root_validator
+    from pydantic.v1.schema import default_ref_template
 else:
     from pydantic import BaseModel, Field, root_validator
+    from pydantic.schema import default_ref_template
 
 from prefect.utilities.callables import get_call_parameters
 from prefect.utilities.importtools import (
@@ -346,6 +348,21 @@ def dict(self, **kwargs) -> Dict[str, Any]:
 
         return super().dict(**kwargs)
 
+    @classmethod
+    def schema(
+        cls, by_alias: bool = True, ref_template: str = default_ref_template
+    ) -> Dict[str, Any]:
+        """
+        Don't use the mixin docstring as the description if this class is missing a
+        docstring.
+        """
+        schema = super().schema(by_alias=by_alias, ref_template=ref_template)
+
+        if not cls.__doc__:
+            schema.pop("description", None)
+
+        return schema
+
 
 def handle_deprecated_infra_overrides_parameter(
     job_variables: Dict[str, Any], infra_overrides: Dict[str, Any]

tests/_internal/compatibility/test_deprecated.py

@@ -305,3 +305,18 @@ def test_handles_setting_none(self, my_deployment_model):
         json_dict = my_deployment.dict()
         assert "job_variables" not in json_dict
         assert json_dict["infra_overrides"] is None
+
+    def test_does_not_override_description_if_none_set(self, my_deployment_model):
+        assert "description" not in my_deployment_model.schema()
+
+    def test_preserves_description_if_present(self):
+        class MyModel(DeprecatedInfraOverridesField, pydantic.BaseModel):
+            """Hey mom"""
+
+            name: str
+            job_variables: Optional[Dict[str, Any]] = pydantic.Field(
+                default_factory=dict,
+                description="Overrides to apply to my deployment infrastructure at runtime.",
+            )
+
+        assert MyModel.schema()["description"] == "Hey mom"