diff --git a/docs/concepts/agent.md b/docs/concepts/agent.md
index 57aff200e04..e719c452643 100644
--- a/docs/concepts/agent.md
+++ b/docs/concepts/agent.md
@@ -65,7 +65,9 @@ Skills can be gated by config/env (see `skills` in [Gateway configuration](/gate
 
 ## Runtime boundaries
 
-Session management, discovery, and tool wiring are OpenClaw-owned.
+The embedded agent runtime is built on the Pi agent core (models, tools, and
+prompt pipeline). Session management, discovery, tool wiring, and channel
+delivery are OpenClaw-owned layers on top of that core.
 
 ## Sessions