fix: prefer named weekday cron examples (#6091)

Co-authored-by: stablegenius49 <185121704+stablegenius49@users.noreply.github.com>

Author: stablegenius49

astrbot/core/tools/cron_tools.py

@@ -30,7 +30,7 @@ class CreateActiveCronTool(FunctionTool[AstrAgentContext]):
             "properties": {
                 "cron_expression": {
                     "type": "string",
-                    "description": "Cron expression defining recurring schedule (e.g., '0 8 * * *').",
+                    "description": "Cron expression defining recurring schedule (e.g., '0 8 * * *' or '0 23 * * mon-fri'). Prefer named weekdays like 'mon-fri' or 'sat,sun' instead of numeric day-of-week ranges such as '1-5' to avoid ambiguity across cron implementations.",
                 },
                 "run_at": {
                     "type": "string",

tests/unit/test_cron_tools.py

@@ -0,0 +1,15 @@
+"""Tests for cron tool metadata."""
+
+from astrbot.core.tools.cron_tools import CreateActiveCronTool
+
+
+def test_create_future_task_cron_description_prefers_named_weekdays():
+    """The cron tool should steer users toward unambiguous named weekdays."""
+    tool = CreateActiveCronTool()
+
+    description = tool.parameters["properties"]["cron_expression"]["description"]
+
+    assert "mon-fri" in description
+    assert "sat,sun" in description
+    assert "1-5" in description
+    assert "avoid ambiguity" in description