From 0d9329bd95f0466472f24f2e6e186718ab9e1d40 Mon Sep 17 00:00:00 2001
From: kshitijk4poor <82637225+kshitijk4poor@users.noreply.github.com>
Date: Sun, 27 Sep 2026 12:56:35 +0530
Subject: [PATCH] test(agent): fold async handoff test and dedupe rationale
 comment

The byte-stability test for the handoff block only re-asserted determinism of
a constant gated on tool-name membership; stable-tier rebuild stability is
already covered by test_system_prompt_restore and test_skills_auto_load. Its
one unique check (block appears exactly once) moves into the positive branch
of the parametrized injection test, and the _prompt helper now takes only the
tool names since every caller used the same model/gates.

The rationale comment lived twice (prompt_builder constant and the
system_prompt call site); keep only the call-site ordering note.
---
 agent/prompt_builder.py           |  3 ---
 tests/agent/test_system_prompt.py | 18 ++++++------------
 2 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/agent/prompt_builder.py b/agent/prompt_builder.py
index 218530f019..6548cf123e 100644
--- a/agent/prompt_builder.py
+++ b/agent/prompt_builder.py
@@ -392,9 +392,6 @@ TASK_COMPLETION_GUIDANCE = (
     "produce. Reporting a blocker honestly is always better than inventing a result."
 )
 
-# Tool-scoped exception to the universal "keep working" guidance. Background delegation's
-# delivery contract requires the parent turn to end before a completed child can re-enter the conversation;
-# manufacturing activity to keep that turn open therefore prevents the dependency from ever arriving.
 ASYNC_HANDOFF_GUIDANCE = (
     "# Async handoff\n"
     "When delegate_task explicitly says background work will deliver its result only after you end the current turn, "
diff --git a/tests/agent/test_system_prompt.py b/tests/agent/test_system_prompt.py
index da0f9a2bf9..a81d95febb 100644
--- a/tests/agent/test_system_prompt.py
+++ b/tests/agent/test_system_prompt.py
@@ -363,13 +363,12 @@ class TestExecutionGuidanceInjection:
 class TestAsyncDelegationHandoffGuidance:
     """A background child cannot re-enter until the parent yields its current turn (#124072)."""
 
-    def _prompt(self, model, *, tool_use_enforcement="auto", execution_guidance="auto",
-                valid_tool_names=("delegate_task", "execute_code")):
+    def _prompt(self, valid_tool_names):
         return _stable_prompt(_make_agent(
             valid_tool_names=list(valid_tool_names),
-            model=model,
-            _tool_use_enforcement=tool_use_enforcement,
-            _execution_guidance=execution_guidance,
+            model="openai/gpt-5.5",
+            _tool_use_enforcement="auto",
+            _execution_guidance="auto",
         ))
 
     @pytest.mark.parametrize("tools,expected", [
@@ -377,19 +376,14 @@ class TestAsyncDelegationHandoffGuidance:
         (("execute_code",), False),
     ])
     def test_handoff_injected_only_with_delegate_task(self, tools, expected):
-        stable = self._prompt("openai/gpt-5.5", valid_tool_names=tools)
+        stable = self._prompt(tools)
         assert ("Async handoff" in stable) is expected
         if expected:
+            assert stable.count("Async handoff") == 1
             # Must follow the generic "keep working" blocks so it reads as their exception.
             assert stable.index("Async handoff") > stable.index("Tool-use enforcement")
             assert stable.index("Async handoff") > stable.index("Execution discipline")
 
-    def test_handoff_prompt_is_byte_stable_across_turns(self):
-        # Stable tier is the prompt-cache prefix: rebuilding it must not drift.
-        first = self._prompt("openai/gpt-5.5")
-        assert first == self._prompt("openai/gpt-5.5")
-        assert first.count("Async handoff") == 1
-
 
 class TestNamedProfileHintIntegration:
     """The same defect through the REAL resolution chain (#72894).