Adding system block with "detailed thinking off" even when system role not present in messages

llama_nemotron_nano_generic_tool_calling.jinja

@@ -1,7 +1,9 @@
 {%- if tools %}
     {{- '<|begin_of_text|><|start_header_id|>system<|end_header_id|>\n\n' -}}
-    {%- if messages[0].role == 'system' -%}
+    {%- if messages[0].role == 'system' and messages[0].content != '' -%}
         {{- messages[0].content + '\n\n' -}}
+    {%- else -%}
+        {{- 'detailed thinking off\n\n' -}}
     {%- endif -%}
     {{- '<AVAILABLE_TOOLS>[' -}}
     {%- for tool in tools -%}
@@ -9,9 +11,13 @@
     {%- endfor -%}
     {{- ']</AVAILABLE_TOOLS>' -}}{{- '<|eot_id|>' -}}
 {%- else %}
-    {%- if messages[0].role == 'system' %}
-        {{- '<|begin_of_text|><|start_header_id|>system<|end_header_id|>\n\n' + messages[0].content + '<|eot_id|>' -}}
+    {{- '<|begin_of_text|><|start_header_id|>system<|end_header_id|>\n\n' -}}
+    {%- if messages[0].role == 'system' and messages[0].content != '' -%}
+        {{- messages[0].content -}}
+    {%- else -%}
+        {{- 'detailed thinking off' -}}
     {%- endif %}
+    {{- '<|eot_id|>' -}}
 {%- endif %}
 {%- for message in messages -%}
     {%- if (message.role == 'user') -%}