diff --git a/DynamoDbEncryption/dafny/DynamoDbEncryption/Model/DynamoDbEncryption.smithy b/DynamoDbEncryption/dafny/DynamoDbEncryption/Model/DynamoDbEncryption.smithy
index eac7192b1..5d21749f6 100644
--- a/DynamoDbEncryption/dafny/DynamoDbEncryption/Model/DynamoDbEncryption.smithy
+++ b/DynamoDbEncryption/dafny/DynamoDbEncryption/Model/DynamoDbEncryption.smithy
@@ -756,7 +756,7 @@ resource DynamoDbKeyBranchKeyIdSupplier{
 @reference(resource: DynamoDbKeyBranchKeyIdSupplier)
 structure DynamoDbKeyBranchKeyIdSupplierReference {}
 
-@javadoc("Get the Branch Key that should be used for wrapping and unwrapping data keys based on the primary key of the item being read or written.")
+@javadoc("Get the Branch Key that should be used for wrapping and unwrapping data keys based on the primary key of the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.")
 operation GetBranchKeyIdFromDdbKey {
   input: GetBranchKeyIdFromDdbKeyInput,
   output: GetBranchKeyIdFromDdbKeyOutput
@@ -764,11 +764,14 @@ operation GetBranchKeyIdFromDdbKey {
 
 //= specification/dynamodb-encryption-client/ddb-encryption-branch-key-id-supplier.md#dynamodbkeybranchkeyidsupplier
 //= type=implication
-//# This operation MUST take in a DDB `Key` structure (and attribute map containing the partition and sort attributes) as input.
+//# This operation MUST take in a DDB `Key` structure
+//# (an attribute map containing the partition and sort attributes,
+//# along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT)
+//# as input.
 @javadoc("Inputs for getting the Branch Key that should be used for wrapping and unwrapping data keys.")
 structure GetBranchKeyIdFromDdbKeyInput {
   @required
-  @javadoc("The partition and sort (if it exists) attributes on the item being read or written.")
+  @javadoc("The partition and sort (if it exists) attributes on the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.")
   ddbKey: Key
 }
 
diff --git a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/DynamoDbKeyBranchKeyIdSupplier.java b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/DynamoDbKeyBranchKeyIdSupplier.java
index 732ab1d55..9c0d33bbc 100644
--- a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/DynamoDbKeyBranchKeyIdSupplier.java
+++ b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/DynamoDbKeyBranchKeyIdSupplier.java
@@ -55,7 +55,7 @@ public software.amazon.cryptography.dbencryptionsdk.dynamodb.internaldafny.types
   }
 
   /**
-   * Get the Branch Key that should be used for wrapping and unwrapping data keys based on the primary key of the item being read or written.
+   * Get the Branch Key that should be used for wrapping and unwrapping data keys based on the primary key of the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.
    *
    * @param input Inputs for getting the Branch Key that should be used for wrapping and unwrapping data keys.
    * @return Outputs for getting the Branch Key that should be used for wrapping and unwrapping data keys.
diff --git a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/IDynamoDbKeyBranchKeyIdSupplier.java b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/IDynamoDbKeyBranchKeyIdSupplier.java
index 7cb53b848..cc3ca1d70 100644
--- a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/IDynamoDbKeyBranchKeyIdSupplier.java
+++ b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/IDynamoDbKeyBranchKeyIdSupplier.java
@@ -8,7 +8,7 @@
 
 public interface IDynamoDbKeyBranchKeyIdSupplier {
   /**
-   * Get the Branch Key that should be used for wrapping and unwrapping data keys based on the primary key of the item being read or written.
+   * Get the Branch Key that should be used for wrapping and unwrapping data keys based on the primary key of the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.
    *
    * @param input Inputs for getting the Branch Key that should be used for wrapping and unwrapping data keys.
    * @return Outputs for getting the Branch Key that should be used for wrapping and unwrapping data keys.
diff --git a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/model/GetBranchKeyIdFromDdbKeyInput.java b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/model/GetBranchKeyIdFromDdbKeyInput.java
index 260c42bcf..0bd67729b 100644
--- a/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/model/GetBranchKeyIdFromDdbKeyInput.java
+++ b/DynamoDbEncryption/runtimes/java/src/main/smithy-generated/software/amazon/cryptography/dbencryptionsdk/dynamodb/model/GetBranchKeyIdFromDdbKeyInput.java
@@ -13,7 +13,7 @@
 public class GetBranchKeyIdFromDdbKeyInput {
 
   /**
-   * The partition and sort (if it exists) attributes on the item being read or written.
+   * The partition and sort (if it exists) attributes on the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.
    */
   private final Map<String, AttributeValue> ddbKey;
 
@@ -22,7 +22,7 @@ protected GetBranchKeyIdFromDdbKeyInput(BuilderImpl builder) {
   }
 
   /**
-   * @return The partition and sort (if it exists) attributes on the item being read or written.
+   * @return The partition and sort (if it exists) attributes on the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.
    */
   public Map<String, AttributeValue> ddbKey() {
     return this.ddbKey;
@@ -38,12 +38,12 @@ public static Builder builder() {
 
   public interface Builder {
     /**
-     * @param ddbKey The partition and sort (if it exists) attributes on the item being read or written.
+     * @param ddbKey The partition and sort (if it exists) attributes on the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.
      */
     Builder ddbKey(Map<String, AttributeValue> ddbKey);
 
     /**
-     * @return The partition and sort (if it exists) attributes on the item being read or written.
+     * @return The partition and sort (if it exists) attributes on the item being read or written, along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT.
      */
     Map<String, AttributeValue> ddbKey();
 
diff --git a/specification/dynamodb-encryption-client/ddb-encryption-branch-key-id-supplier.md b/specification/dynamodb-encryption-client/ddb-encryption-branch-key-id-supplier.md
index c1926ddcc..9359658e0 100644
--- a/specification/dynamodb-encryption-client/ddb-encryption-branch-key-id-supplier.md
+++ b/specification/dynamodb-encryption-client/ddb-encryption-branch-key-id-supplier.md
@@ -51,5 +51,8 @@ and create a Key with these values, using names with the "aws-crypto-attr." remo
 ## DynamoDbKeyBranchKeyIdSupplier
 
 The DynamoDb Key Branch Key Id Supplier is an interface containing the `GetBranchKeyIdFromDdbKey` operation.
-This operation MUST take in a DDB `Key` structure (and attribute map containing the partition and sort attributes) as input.
+This operation MUST take in a DDB `Key` structure
+(an attribute map containing the partition and sort attributes,
+along with the values of any attributes configured as SIGN_AND_INCLUDE_IN_ENCRYPTION_CONTEXT)
+as input.
 This operation MUST return a branch key id (string) as output.