diff --git a/acp_agent/study_agent_acp/mcp_client.py b/acp_agent/study_agent_acp/mcp_client.py
index dc607e9..44c748d 100644
--- a/acp_agent/study_agent_acp/mcp_client.py
+++ b/acp_agent/study_agent_acp/mcp_client.py
@@ -55,7 +55,7 @@ def call_tool(self, name: str, arguments: Dict[str, Any]) -> Dict[str, Any]:
 
     def health_check(self) -> Dict[str, Any]:
         try:
-            if _prefer_oneshot():
+            if _prefer_oneshot() and hasattr(self, "_ping_oneshot"):
                 return anyio.run(self._ping_oneshot)
             self._ensure_session()
             assert self._portal is not None
diff --git a/tests/test_acp_server.py b/tests/test_acp_server.py
index d1c356c..f09a062 100644
--- a/tests/test_acp_server.py
+++ b/tests/test_acp_server.py
@@ -155,7 +155,7 @@ def fake_llm(prompt):
         disease_name="GI bleed",
     )
     assert result["status"] == "ok"
-    assert result["label"] == "yes"
+    assert result["full_result"]["label"] == "yes"
 
 
 @pytest.mark.acp
diff --git a/tests/test_core_tools.py b/tests/test_core_tools.py
index 78595f0..ee1dd52 100644
--- a/tests/test_core_tools.py
+++ b/tests/test_core_tools.py
@@ -87,7 +87,7 @@ def test_phenotype_validation_review_stub():
     result = phenotype_validation_review("GI bleed")
     assert result["mode"] == "stub"
     assert result["label"] == "unknown"
-    assert len(result["phenotype_improvements"]) == 1
+    assert "phenotype_improvements" not in result
 
 
 @pytest.mark.core
diff --git a/tests/test_mcp_tools_registry.py b/tests/test_mcp_tools_registry.py
index 2282018..fcc73c5 100644
--- a/tests/test_mcp_tools_registry.py
+++ b/tests/test_mcp_tools_registry.py
@@ -30,6 +30,7 @@ def test_register_all_tools() -> None:
         "phenotype_fetch_definition",
         "phenotype_list_similar",
         "phenotype_reindex",
+        "phenotype_index_status",
         "phenotype_prompt_bundle",
         "phenotype_recommendation_advice",
         "lint_prompt_bundle",