diff --git a/operator/README.md b/operator/README.md
new file mode 100644
index 00000000..63bf9f37
--- /dev/null
+++ b/operator/README.md
@@ -0,0 +1,6 @@
+# Kubeadm operator
+
+The kubeadm-operator is an experimental project, still WIP.
+Do not use in production.
+
+See [KEP](https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/20190916-kubeadm-operator.md) for more details.
diff --git a/operator/api/v1alpha1/operation_descriptor_types.go b/operator/api/v1alpha1/operation_descriptor_types.go
index 80ac353d..e8e9902a 100644
--- a/operator/api/v1alpha1/operation_descriptor_types.go
+++ b/operator/api/v1alpha1/operation_descriptor_types.go
@@ -34,8 +34,8 @@ type OperatorDescriptor struct {
 
 // UpgradeOperationSpec provide declarative support for the kubeadm upgrade workflow.
 type UpgradeOperationSpec struct {
-	// +optional
-	KubernetesVersion string `json:"kubernetesVersion,omitempty"`
+	// KubernetesVersion specifies the target kubernetes version
+	KubernetesVersion string `json:"kubernetesVersion"`
 
 	// INSERT ADDITIONAL SPEC FIELDS -
 	// Important: Run "make" to regenerate code after modifying this file
@@ -50,5 +50,6 @@ type RenewCertificatesOperationSpec struct {
 
 // CustomOperationSpec enable definition of custom list of RuntimeTaskGroup.
 type CustomOperationSpec struct {
-	Workflow []RuntimeTaskGroup `json:"workflow,omitempty"`
+	// Workflow allows to define a custom list of RuntimeTaskGroup.
+	Workflow []RuntimeTaskGroup `json:"workflow"`
 }
diff --git a/operator/config/crd/bases/operator.kubeadm.x-k8s.io_operations.yaml b/operator/config/crd/bases/operator.kubeadm.x-k8s.io_operations.yaml
index 92f49ba2..e8cc2af9 100644
--- a/operator/config/crd/bases/operator.kubeadm.x-k8s.io_operations.yaml
+++ b/operator/config/crd/bases/operator.kubeadm.x-k8s.io_operations.yaml
@@ -406,6 +406,7 @@ spec:
               description: CustomOperation enable definition of custom list of RuntimeTaskGroup.
               properties:
                 workflow:
+                  description: Workflow allows to define a custom list of RuntimeTaskGroup.
                   items:
                     properties:
                       apiVersion:
@@ -1448,10 +1449,6 @@ spec:
                                     description: NodeName is a request to schedule
                                       this RuntimeTask onto a specific node.
                                     type: string
-                                  paused:
-                                    description: Paused indicates that the RuntimeTask
-                                      is paused.
-                                    type: boolean
                                   recoveryMode:
                                     description: RecoveryMode sets the strategy to
                                       use when a command is failed.
@@ -1520,6 +1517,8 @@ spec:
                         type: object
                     type: object
                   type: array
+              required:
+              - workflow
               type: object
             executionMode:
               description: ExecutionMode indicates how the controller should handle
@@ -1538,7 +1537,10 @@ spec:
                 workflow.
               properties:
                 kubernetesVersion:
+                  description: KubernetesVersion specifies the target kubernetes version
                   type: string
+              required:
+              - kubernetesVersion
               type: object
           type: object
         status:
diff --git a/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetaskgroups.yaml b/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetaskgroups.yaml
index 6e642d36..335f9494 100644
--- a/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetaskgroups.yaml
+++ b/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetaskgroups.yaml
@@ -935,9 +935,6 @@ spec:
                       description: NodeName is a request to schedule this RuntimeTask
                         onto a specific node.
                       type: string
-                    paused:
-                      description: Paused indicates that the RuntimeTask is paused.
-                      type: boolean
                     recoveryMode:
                       description: RecoveryMode sets the strategy to use when a command
                         is failed.
diff --git a/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetasks.yaml b/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetasks.yaml
index 8662e4f9..7c5ae280 100644
--- a/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetasks.yaml
+++ b/operator/config/crd/bases/operator.kubeadm.x-k8s.io_runtimetasks.yaml
@@ -446,9 +446,6 @@ spec:
               description: NodeName is a request to schedule this RuntimeTask onto
                 a specific node.
               type: string
-            paused:
-              description: Paused indicates that the RuntimeTask is paused.
-              type: boolean
             recoveryMode:
               description: RecoveryMode sets the strategy to use when a command is
                 failed.
@@ -460,7 +457,7 @@ spec:
           properties:
             commandProgress:
               description: CommandProgress Please note that this field is only for
-                allowing a better
+                allowing a better visal representation of status
               type: string
             completionTime:
               description: CompletionTime represents time when the RuntimeTask was