diff --git a/tests/tools/test_skills_tool.py b/tests/tools/test_skills_tool.py
index 506a47eeb6..07b6b58e01 100644
--- a/tests/tools/test_skills_tool.py
+++ b/tests/tools/test_skills_tool.py
@@ -150,6 +150,31 @@ class TestRequiredEnvironmentVariablesNormalization:
         assert _is_env_var_persisted("EMPTY_HOST_KEY", {}) is False
         assert _is_env_var_persisted("FILLED_KEY", {}) is True
 
+    def test_active_profile_secret_scope_satisfies_requirement(self):
+        """Cron workers must accept a value hydrated from this profile's vault."""
+        from agent import secret_scope
+        from tools.skills_tool import _is_env_var_persisted
+
+        secret_scope.set_multiplex_active(True)
+        token = secret_scope.set_secret_scope({"VAULT_SKILL_API_KEY": "vault-value"})
+        try:
+            assert _is_env_var_persisted("VAULT_SKILL_API_KEY", {}) is True
+        finally:
+            secret_scope.reset_secret_scope(token)
+            secret_scope.set_multiplex_active(False)
+
+    def test_unscoped_multiplex_requirement_does_not_read_process_environment(self, monkeypatch):
+        """A worker without a profile scope must keep the fail-closed boundary."""
+        from agent import secret_scope
+        from tools.skills_tool import _is_env_var_persisted
+
+        monkeypatch.setenv("OTHER_PROFILE_SKILL_API_KEY", "other-profile-value")
+        secret_scope.set_multiplex_active(True)
+        try:
+            assert _is_env_var_persisted("OTHER_PROFILE_SKILL_API_KEY", {}) is False
+        finally:
+            secret_scope.set_multiplex_active(False)
+
 
 # ---------------------------------------------------------------------------
 # _get_category_from_path
diff --git a/tools/skills_tool_setup.py b/tools/skills_tool_setup.py
index 243f7b0eb6..17d6dcf6ac 100644
--- a/tools/skills_tool_setup.py
+++ b/tools/skills_tool_setup.py
@@ -3,7 +3,6 @@
 ``load_env``) stays there and is read lazily at call time so origin-module patches are honored."""
 
 import logging
-import os
 import re
 from enum import Enum
 from typing import Any, Dict, List
@@ -126,8 +125,20 @@ def _is_gateway_surface() -> bool:
 
 
 def _is_env_var_persisted(var_name: str, env_snapshot: Dict[str, str]) -> bool:
-    """Set (non-empty) in the .env snapshot, else in the process environment."""
-    return bool(env_snapshot[var_name] if var_name in env_snapshot else os.getenv(var_name))
+    """Return whether a requirement is present in this profile's secret sources.
+
+    The snapshot keeps the existing ``.env`` precedence.  A miss must use
+    ``get_secret`` rather than reading ``os.environ`` directly so an active
+    multiplex worker can see its hydrated external secrets without seeing a
+    different profile's process environment.
+    """
+    if var_name in env_snapshot:
+        return bool(env_snapshot[var_name])
+    try:
+        from agent.secret_scope import UnscopedSecretError, get_secret
+        return bool(get_secret(var_name))
+    except UnscopedSecretError:
+        return False
 
 
 def _build_setup_note(