diff --git b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/transforms/model/CollectionOfErrors.java a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/transforms/model/CollectionOfErrors.java
index 7a2ca9b0..db01d961 100644
--- b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/transforms/model/CollectionOfErrors.java
+++ a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/transforms/model/CollectionOfErrors.java
@@ -4,6 +4,7 @@
 package software.amazon.cryptography.dbencryptionsdk.dynamodb.transforms.model;
 
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class CollectionOfErrors extends RuntimeException {
 
@@ -134,6 +135,14 @@ public class CollectionOfErrors extends RuntimeException {
     }
 
     public CollectionOfErrors build() {
+      if (!(this.list == null || this.list.isEmpty())) {
+        this.message =
+          this.message +
+          " String representation of Exceptions in list.\n" +
+          this.list.stream()
+            .map(ex -> ex.getClass().getSimpleName() + ": " + ex.getMessage())
+            .collect(Collectors.joining("\n"));
+      }
       return new CollectionOfErrors(this);
     }
   }