Improve template comments

fred_api/messenger/email.proto

@@ -32,6 +32,8 @@ message Email
     string type = 12;
     // Name of the templates for subject and body in text and HTML versions.
     // Subject and body templates are required.
+    //
+    // If template UUIDs are provided, respective template names are ignored and play only a descriptive role.
     string subject_template = 4;
     string body_template = 5;
     string body_template_html = 6;
@@ -40,6 +42,9 @@ message Email
     // List of attachment UUIDs
     repeated Uuid attachments = 8;
     // UUID of the templates for subject and body in text and HTML versions.
+    //
+    // If UUIDs are provided, template names play only a descriptive role.
+    // In such case, the client is responsible for using matching template names and UUIDs.
     Uuid subject_template_uuid = 9;
     Uuid body_template_uuid = 10;
     Uuid body_template_html_uuid = 11;

fred_api/messenger/sms.proto

@@ -17,11 +17,16 @@ message Sms
     string recipient = 1;
     // Message type - optional descriptive parameter.
     string type = 5;
-    // Name of the template for the message content.
+    // Required. Name of the template for the message content.
+    //
+    // If template UUID is provided, the template name is ignored and play only a descriptive role.
     string body_template = 2;
     // A context used to render the message content from template.
     google.protobuf.Struct context = 3;
     // UUID of the template for the message content.
+    //
+    // If UUID is provided, the template name plays only a descriptive role.
+    // In such case, the client is responsible for using matching template name and UUID.
     Uuid body_template_uuid = 4;
 }