diff --git a/docs/cli/discovery_cli.md b/docs/cli/discovery_cli.md
index bb50e8e..a6605b7 100644
--- a/docs/cli/discovery_cli.md
+++ b/docs/cli/discovery_cli.md
@@ -1,6 +1,6 @@
 # discovery_cli
 
-A development tool for testing the UDP multicast discovery layer. Announces a node on the local network and prints peers as they appear and disappear.
+A development tool for testing the discovery layer. Announces a node on the local network via UDP multicast and prints peers as they appear and disappear.
 
 ---
 
diff --git a/docs/discovery.md b/docs/discovery.md
index f3f6d7a..61faeb3 100644
--- a/docs/discovery.md
+++ b/docs/discovery.md
@@ -43,12 +43,18 @@ A node may set multiple bits — a relay that also archives sets both `RELAY` an
 
 ### Behaviour
 
-- Nodes send announcements periodically (e.g. every 5 s) and immediately on startup
+- Nodes send announcements periodically (e.g. every 5 s) and immediately on startup via multicast
 - No daemon — the node process itself sends and listens; no background service required
-- On receiving an announcement, the control plane records the peer (address, port, name, function) and can initiate a transport connection if needed
+- On receiving an announcement the control plane records the peer (address, port, name, function) and can initiate a transport connection if needed
 - A node going silent for a configured number of announcement intervals is considered offline
 - Announcements are informational only — the hub validates identity at connection time
 
+#### Targeted replies
+
+Multicast is only used for the periodic keep-alive broadcast. When a node receives an announcement from a peer it does not yet know, or detects that a known peer has restarted (its `site_id` changed for the same address and port), it sends an **immediate unicast reply** directly back to that peer's IP address. This ensures the new or restarted peer learns about this node quickly without waiting up to `interval_ms`, while avoiding a multicast blast that would unnecessarily wake every other node on the subnet.
+
+Steady-state keepalive packets from already-known peers do not trigger any reply.
+
 ### No Avahi/Bonjour Dependency
 
 The system does not link against, depend on, or interact with Avahi or Bonjour. It opens a raw UDP multicast socket directly, which requires only standard POSIX socket APIs. This keeps the runtime dependency footprint minimal and the behaviour predictable.