diff --git a/vllm/v1/worker/workspace.py b/vllm/v1/worker/workspace.py
index b0d2b5f87cf..a8f97e7cd47 100644
--- a/vllm/v1/worker/workspace.py
+++ b/vllm/v1/worker/workspace.py
@@ -27,6 +27,9 @@ _GiB = 1024**3
 # Global workspace manager instance
 _manager: "WorkspaceManager | None" = None
 
+# each pool reuses a single backing allocation per ubatch
+# keep communication in a separate pool so it cannot alias with default
+# workspace tensors that may still be live while DCP collectives run.
 DEFAULT_WORKSPACE_POOL = "default"
 COMM_WORKSPACE_POOL = "comm"