diff --git a/build/bazel/remote/execution/v2/remote_execution.proto b/build/bazel/remote/execution/v2/remote_execution.proto
index 40e34917..8224f1a1 100644
--- a/build/bazel/remote/execution/v2/remote_execution.proto
+++ b/build/bazel/remote/execution/v2/remote_execution.proto
@@ -1995,15 +1995,18 @@ message SpliceBlobRequest {
   // omitted.
   string instance_name = 1;
 
-  // Expected digest of the spliced blob. The client SHOULD set this field due
+  // Expected digest of the spliced blob. The client MUST set this field due
   // to the following reasons:
   //  1. It allows the server to perform an early existence check of the blob
-  //     before spending the splicing effort, as described in the
-  //     [ContentAddressableStorage.SpliceBlob][build.bazel.remote.execution.v2.ContentAddressableStorage.SpliceBlob]
+  //     or existing chunks that assemble the blob before spending the splicing
+  //     effort, as described in the [ContentAddressableStorage.SpliceBlob][build.bazel.remote.execution.v2.ContentAddressableStorage.SpliceBlob]
   //     documentation.
   //  2. It allows servers with different storage backends to dispatch the
   //     request to the correct storage backend based on the size and/or the
   //     hash of the blob.
+  //  3. If chunking information already exists for the blob, it allows
+  //     the server to keep the existing chunking information or replace it with
+  //     new chunking information.
   Digest blob_digest = 2;
 
   // The ordered list of digests of the chunks which need to be concatenated to