diff --git a/tools/AquaSynthDingsMcp/README.md b/tools/AquaSynthDingsMcp/README.md
index f5dc97b..bfb09e5 100644
--- a/tools/AquaSynthDingsMcp/README.md
+++ b/tools/AquaSynthDingsMcp/README.md
@@ -8,6 +8,13 @@ All MCP instances are command bridges. One persistent
 Aqua synthesis child, mixer, master volume, and mute state. Windows Volume
 Mixer and MCP volume tools address the same session.
 
+Do not register this STDIO bridge globally in an agent harness that creates a
+separate MCP client for every root agent, subagent, or critic. STDIO ownership
+means one resident .NET bridge per client even though audio authority is already
+shared by `AquaSynthDingsHost.exe`. Keep the bridge disabled in that topology,
+use the direct CLI for local smokes, or expose one supervised Streamable HTTP MCP
+server when notifications need to be available across many concurrent agents.
+
 ```powershell
 dotnet run --project tools/AquaSynthDingsMcp
 ```