fix(guardrails): keep Agent 365 missing-secret startup error readable after log redaction

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/guardrails/guardrail_hooks/agent_365/__init__.py

@@ -29,7 +29,9 @@ def initialize_guardrail(litellm_params: "LitellmParams", guardrail: "Guardrail"
     if not client_id:
         raise ValueError("Microsoft Agent 365: client_id is required")
     if not client_secret:
-        raise ValueError("Microsoft Agent 365: client_secret (or api_key) is required")
+        raise ValueError(
+            "Microsoft Agent 365: client secret is required. Set client_secret, api_key, or AGENT365_CLIENT_SECRET"
+        )
 
     guardrail_name: Final = guardrail.get("guardrail_name")
     if not guardrail_name:

tests/test_litellm/proxy/guardrails/guardrail_hooks/test_agent_365.py

@@ -7,6 +7,7 @@ import pytest
 from fastapi import HTTPException
 
 from litellm.exceptions import Timeout as LitellmTimeout
+from litellm.litellm_core_utils.secret_redaction import redact_string
 from litellm.proxy._types import UserAPIKeyAuth
 from litellm.proxy.guardrails.guardrail_hooks.agent_365 import (
     Agent365Guardrail,
@@ -165,8 +166,9 @@ class TestInitializeGuardrail:
             tenant_id="tenant-abc",
             client_id="client-xyz",
         )
-        with pytest.raises(ValueError, match="client_secret"):
+        with pytest.raises(ValueError, match="client_secret") as exc_info:
             initialize_guardrail(params, {"guardrail_name": "a365"})
+        assert redact_string(str(exc_info.value)) == str(exc_info.value)
 
     def test_env_var_fallbacks(self, monkeypatch):
         monkeypatch.delenv("AGENT365_RESOURCE_APP_ID", raising=False)