diff --git a/homeassistant/helpers/llm.py b/homeassistant/helpers/llm.py
index d1ce3047e78..535e2af4d04 100644
--- a/homeassistant/helpers/llm.py
+++ b/homeassistant/helpers/llm.py
@@ -250,9 +250,10 @@ class AssistAPI(API):
         prompt = [
             (
                 "Call the intent tools to control Home Assistant. "
+                "Do not pass the domain to the intent tools as a list. "
                 "When controlling a device, prefer passing just its name and its domain "
                 "(what comes before the dot in its entity id). "
-                "When controlling an area, prefer passing just area name and a single domain."
+                "When controlling an area, prefer passing just area name and domain."
             )
         ]
         area: ar.AreaEntry | None = None
diff --git a/tests/helpers/test_llm.py b/tests/helpers/test_llm.py
index 672b6a6642b..63c1214dd6d 100644
--- a/tests/helpers/test_llm.py
+++ b/tests/helpers/test_llm.py
@@ -423,9 +423,10 @@ async def test_assist_api_prompt(
     )
     first_part_prompt = (
         "Call the intent tools to control Home Assistant. "
+        "Do not pass the domain to the intent tools as a list. "
         "When controlling a device, prefer passing just its name and its domain "
         "(what comes before the dot in its entity id). "
-        "When controlling an area, prefer passing just area name and a single domain."
+        "When controlling an area, prefer passing just area name and domain."
     )
     no_timer_prompt = "This device does not support timers."