diff --git a/tools/delegate_tool.py b/tools/delegate_tool.py
index 8a5a060fd48..27564306ee9 100644
--- a/tools/delegate_tool.py
+++ b/tools/delegate_tool.py
@@ -3185,6 +3185,11 @@ def _build_top_level_description() -> str:
         "- Mechanical multi-step work with no reasoning needed -> use execute_code\n"
         "- Single tool call -> just call the tool directly\n"
         "- Tasks needing user interaction -> subagents cannot use clarify\n"
+        "- Critical-path, urgent, or tightly-coupled work -> keep it local. A "
+        "request for depth, research, or investigation does NOT by itself mean "
+        "delegate: if the work blocks your next step, must interleave with your "
+        "own reasoning, or is the main deliverable rather than independent side "
+        "work, do it yourself. Delegate the independent branches, keep the spine.\n"
         "- Durable long-running work that must outlive the current turn -> "
         "use cronjob (action='create') or terminal(background=True, "
         "notify_on_complete=True) instead. Background delegations are NOT "