diff --git a/navi/core/subagent_runner.py b/navi/core/subagent_runner.py
index d147e18..b2a2330 100644
--- a/navi/core/subagent_runner.py
+++ b/navi/core/subagent_runner.py
@@ -101,9 +101,29 @@
         exclude = set(exclude_tools or [])
 
         tool_source = profile.subagent_tools if profile.subagent_tools else profile.enabled_tools
+
+        # If subagent_tools is a strict whitelist, filter mcp_servers to only
+        # include MCP tools explicitly listed in the whitelist.  This prevents
+        # a profile from accidentally granting sub-agents access to MCP servers
+        # that are meant for the main agent only.
+        mcp_servers = profile.mcp_servers
+        if profile.subagent_tools:
+            mcp_tool_names = {n for n in profile.subagent_tools if n.startswith("mcp:")}
+            if mcp_tool_names:
+                filtered_mcp_servers: dict[str, list[str]] = {}
+                for server_name, groups in (profile.mcp_servers or {}).items():
+                    for group_name in groups:
+                        for tool_name in self._mcp_manager.resolve_group(server_name, group_name):
+                            full_name = f"mcp:{server_name}:{tool_name}"
+                            if full_name in mcp_tool_names:
+                                filtered_mcp_servers.setdefault(server_name, []).append(group_name)
+                mcp_servers = filtered_mcp_servers or None
+            else:
+                mcp_servers = None
+
         tools = [
             t
-            for t in build_tool_list(tool_source, profile.mcp_servers, self._tools, self._mcp_manager)
+            for t in build_tool_list(tool_source, mcp_servers, self._tools, self._mcp_manager)
             if t.name not in exclude
         ]
         tool_schemas = [t.schema() for t in tools]