diff --git a/agent/memory_manager.py b/agent/memory_manager.py
index 62cbd6ae1a..f5bcd4247e 100644
--- a/agent/memory_manager.py
+++ b/agent/memory_manager.py
@@ -1,17 +1,14 @@
-"""MemoryManager — orchestrates the built-in memory provider plus at most
-ONE external plugin memory provider.
+"""MemoryManager — orchestrates memory providers for the agent.
 
 Single integration point in run_agent.py. Replaces scattered per-backend
 code with one manager that delegates to registered providers.
 
-The BuiltinMemoryProvider is always registered first and cannot be removed.
-Only ONE external (non-builtin) provider is allowed at a time — attempting
-to register a second external provider is rejected with a warning.  This
+Only ONE external plugin provider is allowed at a time — attempting to
+register a second external provider is rejected with a warning.  This
 prevents tool schema bloat and conflicting memory backends.
 
 Usage in run_agent.py:
     self._memory_manager = MemoryManager()
-    self._memory_manager.add_provider(BuiltinMemoryProvider(...))
     # Only ONE of these:
     self._memory_manager.add_provider(plugin_provider)
 
diff --git a/agent/memory_provider.py b/agent/memory_provider.py
index 535338f4ee..a8a0688c30 100644
--- a/agent/memory_provider.py
+++ b/agent/memory_provider.py
@@ -1,17 +1,16 @@
 """Abstract base class for pluggable memory providers.
 
-Memory providers give the agent persistent recall across sessions. One
-external provider is active at a time alongside the always-on built-in
-memory (MEMORY.md / USER.md). The MemoryManager enforces this limit.
+Memory providers give the agent persistent recall across sessions.
+The MemoryManager enforces a one-external-provider limit to prevent
+tool schema bloat and conflicting memory backends.
 
-Built-in memory is always active as the first provider and cannot be removed.
-External providers (Honcho, Hindsight, Mem0, etc.) are additive — they never
-disable the built-in store. Only one external provider runs at a time to
-prevent tool schema bloat and conflicting memory backends.
+External providers (Honcho, Hindsight, Mem0, etc.) are registered
+and managed via MemoryManager. Only one external provider runs at a
+time.
 
 Registration:
-  1. Built-in: BuiltinMemoryProvider — always present, not removable.
-  2. Plugins: Ship in plugins/memory/<name>/, activated by memory.provider config.
+  Plugins ship in plugins/memory/<name>/ and are activated via
+  the memory.provider config key.
 
 Lifecycle (called by MemoryManager, wired in run_agent.py):
   initialize()          — connect, create resources, warm up