diff --git a/homeassistant/components/google_generative_ai_conversation/config_flow.py b/homeassistant/components/google_generative_ai_conversation/config_flow.py
index 50b626f553c..b559888cc5f 100644
--- a/homeassistant/components/google_generative_ai_conversation/config_flow.py
+++ b/homeassistant/components/google_generative_ai_conversation/config_flow.py
@@ -181,8 +181,7 @@ async def google_generative_ai_config_option_schema(
     schema = {
         vol.Optional(
             CONF_PROMPT,
-            description={"suggested_value": options.get(CONF_PROMPT)},
-            default=DEFAULT_PROMPT,
+            description={"suggested_value": options.get(CONF_PROMPT, DEFAULT_PROMPT)},
         ): TemplateSelector(),
         vol.Optional(
             CONF_LLM_HASS_API,
diff --git a/homeassistant/components/google_generative_ai_conversation/conversation.py b/homeassistant/components/google_generative_ai_conversation/conversation.py
index ad50c544ac7..21d26ab5616 100644
--- a/homeassistant/components/google_generative_ai_conversation/conversation.py
+++ b/homeassistant/components/google_generative_ai_conversation/conversation.py
@@ -205,15 +205,6 @@ class GoogleGenerativeAIConversationEntity(
             messages = [{}, {}]
 
         try:
-            prompt = template.Template(
-                self.entry.options.get(CONF_PROMPT, DEFAULT_PROMPT), self.hass
-            ).async_render(
-                {
-                    "ha_name": self.hass.config.location_name,
-                },
-                parse_result=False,
-            )
-
             if llm_api:
                 empty_tool_input = llm.ToolInput(
                     tool_name="",
@@ -226,9 +217,24 @@ class GoogleGenerativeAIConversationEntity(
                     device_id=user_input.device_id,
                 )
 
-                prompt = (
-                    await llm_api.async_get_api_prompt(empty_tool_input) + "\n" + prompt
+                api_prompt = await llm_api.async_get_api_prompt(empty_tool_input)
+
+            else:
+                api_prompt = llm.PROMPT_NO_API_CONFIGURED
+
+            prompt = "\n".join(
+                (
+                    api_prompt,
+                    template.Template(
+                        self.entry.options.get(CONF_PROMPT, DEFAULT_PROMPT), self.hass
+                    ).async_render(
+                        {
+                            "ha_name": self.hass.config.location_name,
+                        },
+                        parse_result=False,
+                    ),
                 )
+            )
 
         except TemplateError as err:
             LOGGER.error("Error rendering prompt: %s", err)
diff --git a/tests/components/google_generative_ai_conversation/snapshots/test_conversation.ambr b/tests/components/google_generative_ai_conversation/snapshots/test_conversation.ambr
index ebc918bbf31..112e1f91b55 100644
--- a/tests/components/google_generative_ai_conversation/snapshots/test_conversation.ambr
+++ b/tests/components/google_generative_ai_conversation/snapshots/test_conversation.ambr
@@ -29,7 +29,10 @@
       dict({
         'history': list([
           dict({
-            'parts': 'Answer in plain text. Keep it simple and to the point.',
+            'parts': '''
+              Only if the user wants to control a device, tell them to edit the AI configuration and allow access to Home Assistant.
+              Answer in plain text. Keep it simple and to the point.
+            ''',
             'role': 'user',
           }),
           dict({
@@ -79,7 +82,10 @@
       dict({
         'history': list([
           dict({
-            'parts': 'Answer in plain text. Keep it simple and to the point.',
+            'parts': '''
+              Only if the user wants to control a device, tell them to edit the AI configuration and allow access to Home Assistant.
+              Answer in plain text. Keep it simple and to the point.
+            ''',
             'role': 'user',
           }),
           dict({