diff --git a/app/discovery/servers.py b/app/discovery/servers.py
index 15eb4ae..f70d0ea 100644
--- a/app/discovery/servers.py
+++ b/app/discovery/servers.py
@@ -57,7 +57,7 @@ def discover_mcp_servers(plugins_root: Path) -> dict:
     if cti_pipeline_path.exists():
         cti_metadata = _safe_load_metadata(cti_pipeline_path) or {
             "display_name": "CTI Pipeline",
-            "default_enabled": True,
+            "default_enabled": False,
             "description": (
                 "CTI ingest -> STIX -> adversary -> "
                 "-> operation -> detection-validation tools."
diff --git a/app/workflows/plan_execute.py b/app/workflows/plan_execute.py
index 0cea98a..419e506 100644
--- a/app/workflows/plan_execute.py
+++ b/app/workflows/plan_execute.py
@@ -188,11 +188,9 @@ async def run(adversary_emulation_task: str, lm_obj=None, rag_context=None,
 
     # Resolve which MCP servers to spawn
     if not enabled_servers:
-        # Default to both caldera_core and cti_pipeline so the planner has
-        # the full CTI -> STIX -> deploy -> operation -> detections toolset
-        # out of the box. cti_pipeline is filtered out below if its server
-        # file is missing (graceful fall-back to caldera_core-only mode).
-        enabled_servers = ["caldera_core", "cti_pipeline"]
+        # Default to caldera_core only. cti_pipeline is opt-in: the GUI ticks
+        # it on when STIX is selected, and callers can pass it explicitly.
+        enabled_servers = ["caldera_core"]
     if server_registry is None:
         # Fallback used only when run() is invoked without a registry (e.g. tests).
         # mcp_server.py lives one directory up after the workflows/ split.
@@ -210,7 +208,7 @@ async def run(adversary_emulation_task: str, lm_obj=None, rag_context=None,
                 "path": cti_pipeline_server_path,
                 "metadata": {
                     "display_name": "CTI Pipeline",
-                    "default_enabled": True,
+                    "default_enabled": False,
                     "description": (
                         "CTI ingest -> STIX -> adversary -> "
                         "deploy -> operation -> detection-validation tools."
diff --git a/mcp_server.py b/mcp_server.py
index 105a47f..c9fc579 100644
--- a/mcp_server.py
+++ b/mcp_server.py
@@ -111,7 +111,7 @@ def _resolve_pipeline_file(path_value: str, *, data_subdirs: tuple[str, ...] = (
 MCP_METADATA = {
     "id": "cti_pipeline",
     "display_name": "CTI Pipeline",
-    "default_enabled": True,
+    "default_enabled": False,
     "description": (
         "End-to-end CTI ingest tools: PDF/HTML -> STIX 2.1 bundle -> "
         "adversary -> operation "