diff --git a/lez/sequencer/service/rpc/src/lib.rs b/lez/sequencer/service/rpc/src/lib.rs
index fc3a94d6..929d844c 100644
--- a/lez/sequencer/service/rpc/src/lib.rs
+++ b/lez/sequencer/service/rpc/src/lib.rs
@@ -96,6 +96,10 @@ pub trait Rpc {
     /// Admin-only in effect: the L1 rejects the config op unless this
     /// sequencer's key is the channel admin (`keys[0]` of the current roster).
     ///
+    /// There is no caller auth — anyone who can reach the RPC port can invoke
+    /// this, so the server must not be exposed beyond trusted clients (see
+    /// the sequencer's `--listen-address`).
+    ///
     /// `Ok(())` only means the signed config op was queued locally (like
     /// block publishing), not that L1 accepted it: acceptance is asynchronous,
     /// and a rejection (e.g. non-admin signer) is not reported here — it only