diff --git a/nix/templates/harness-base.nix b/nix/templates/harness-base.nix
index 227e8c01..b7b25ee8 100644
--- a/nix/templates/harness-base.nix
+++ b/nix/templates/harness-base.nix
@@ -839,6 +839,14 @@
     # without the trigger the daemon would exit 0 quietly and the
     # MCP would have no backend until next restart. With the watcher
     # the daemon comes alive in the same boot cycle as provisioning.
+    #
+    # `PathExists=` fires at activation if the file is already there
+    # (covers re-deploys + restarts after first provisioning); the
+    # underlying inotify watch picks up subsequent creates (covers
+    # first-boot race). Manager mounts state at `/state` (legacy
+    # path), sub-agents at `/agents/<label>/state` (per
+    # lifecycle.rs's `notes_mount`); `PathExistsGlob=` matches both
+    # without needing the agent name at module-eval time.
     systemd.paths.hive-matrix-daemon = lib.mkIf config.hyperhive.matrix.enable {
       description = "trigger hive-matrix-daemon when matrix-token appears";
       wantedBy = [ "multi-user.target" ];