diff --git a/tests/integration/test_mcp_routes.py b/tests/integration/test_mcp_routes.py
index 87d9f2d..0d6708e 100644
--- a/tests/integration/test_mcp_routes.py
+++ b/tests/integration/test_mcp_routes.py
@@ -579,3 +579,113 @@ def test_yarn_error_returns_502_with_detail(tmp_path, monkeypatch):
     detail = r.json()["detail"]
     assert "YARN connection failed" in detail
     assert "Connection refused" in detail
+
+
+def test_external_job_status_returns_502_on_yarn_error(tmp_path):
+    """get_external_job_status uses get_application_status under the
+    hood — same handler, same 502, same detail."""
+    from unittest.mock import patch
+    from spark_executor.core.yarn_client import YarnError
+
+    connection_store.store.save(
+        Connection(
+            name="prod",
+            master="yarn",
+            yarn_rm_url="http://ccam1:8088",
+        )
+    )
+    c = TestClient(app)
+    with patch(
+        "spark_executor.tools.external_jobs.get_application_status",
+        side_effect=YarnError("YARN application 'application_xxx' not found"),
+    ):
+        r = c.post(
+            "/get_external_job_status",
+            json={"application_id": "application_1740000000001_0001", "connection_name": "prod"},
+        )
+    assert r.status_code == 502
+    assert "not found" in r.json()["detail"]
+
+
+def test_external_job_result_returns_502_on_yarn_error(tmp_path):
+    """get_external_job_result also uses get_application_status (same
+    underlying YARN endpoint), and exercises the same YarnError path."""
+    from unittest.mock import patch
+    from spark_executor.core.yarn_client import YarnError
+
+    connection_store.store.save(
+        Connection(
+            name="prod",
+            master="yarn",
+            yarn_rm_url="http://ccam1:8088",
+        )
+    )
+    c = TestClient(app)
+    with patch(
+        "spark_executor.tools.external_jobs.get_application_status",
+        side_effect=YarnError("YARN connection failed: ConnectError: Connection refused"),
+    ):
+        r = c.post(
+            "/get_external_job_result",
+            json={"application_id": "application_1740000000001_0001", "connection_name": "prod"},
+        )
+    assert r.status_code == 502
+    assert "YARN connection failed" in r.json()["detail"]
+
+
+def test_external_job_logs_returns_502_on_yarn_error(tmp_path):
+    """get_external_job_logs uses get_application_logs — different
+    function, but raises YarnError the same way. Handler must catch
+    it the same way."""
+    from unittest.mock import patch
+    from spark_executor.core.yarn_client import YarnError
+
+    connection_store.store.save(
+        Connection(
+            name="prod",
+            master="yarn",
+            yarn_rm_url="http://ccam1:8088",
+        )
+    )
+    c = TestClient(app)
+    with patch(
+        "spark_executor.tools.external_jobs.get_application_logs",
+        side_effect=YarnError("YARN GET logs returned HTTP 500: cluster overloaded"),
+    ):
+        r = c.post(
+            "/get_external_job_logs",
+            json={
+                "application_id": "application_1740000000001_0001",
+                "connection_name": "prod",
+                "tail_chars": 5000,
+            },
+        )
+    assert r.status_code == 502
+    assert "YARN GET logs returned HTTP 500" in r.json()["detail"]
+    assert "cluster overloaded" in r.json()["detail"]
+
+
+def test_list_applications_returns_502_on_yarn_error(tmp_path):
+    """list_applications uses list_applications_yarn — yet another
+    YARN-touching tool. Same YarnError -> 502 contract."""
+    from unittest.mock import patch
+    from spark_executor.core.yarn_client import YarnError
+
+    connection_store.store.save(
+        Connection(
+            name="prod",
+            master="yarn",
+            yarn_rm_url="http://ccam1:8088",
+        )
+    )
+    c = TestClient(app)
+    with patch(
+        "spark_executor.tools.external_jobs.list_applications_yarn",
+        side_effect=YarnError("YARN list applications failed: 503 Service Unavailable"),
+    ):
+        r = c.post(
+            "/list_applications",
+            json={"connection_name": "prod"},
+        )
+    assert r.status_code == 502
+    assert "YARN list applications failed" in r.json()["detail"]