diff --git a/buf/plugin/check/v1/annotation.proto b/buf/plugin/check/v1/annotation.proto
index 7698705..8ef93a9 100644
--- a/buf/plugin/check/v1/annotation.proto
+++ b/buf/plugin/check/v1/annotation.proto
@@ -54,4 +54,16 @@ message Annotation {
   // this may reference the deleted FileDescriptor in against_file_descriptors, while file_location
   // will not be present.
   buf.plugin.descriptor.v1.FileLocation against_file_location = 4;
+  // A URL that provides more human-readable information about the rule in question.
+  //
+  // Optional.
+  string documentation_link = 5;
+  // An optional identifier that can help refine exactly how the rule was violated.
+  //
+  // Optional.
+  //
+  // Simple rules will probably not require this level of detail because it is obvious, but
+  // for more complex logic (such as checks involving external systems), it can be helpful to
+  // provide an identifier that narrows down why the rule failed.
+  string failure_code = 6;
 }