[Auto Sync] Update tool_chat_template_deepseekv31.jinja (20251210) (#14837)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Jue Wang <zjuwangjue@gmail.com>

Author: 3 people

examples/chat_template/tool_chat_template_deepseekv31.jinja

@@ -19,7 +19,11 @@
 {% if tools is defined and tools is not none %}
   {% set tool_ns = namespace(text='## Tools\nYou have access to the following tools:\n') %}
   {% for tool in tools %}
-    {% set tool_ns.text = tool_ns.text + '\n### ' + tool.function.name + '\nDescription: ' + tool.function.description + '\n\nParameters: ' + (tool.function.parameters | tojson) + '\n' %}
+    {% if tool.function.description is not none %}
+      {% set tool_ns.text = tool_ns.text + '\n### ' + tool.function.name + '\nDescription: ' + tool.function.description + '\n\nParameters: ' + (tool.function.parameters | tojson) + '\n' %}
+    {% else %}
+      {% set tool_ns.text = tool_ns.text + '\n### ' + tool.function.name + '\n\nParameters: ' + (tool.function.parameters | tojson) + '\n' %}
+    {% endif %}
   {% endfor %}
   {% set tool_ns.text = tool_ns.text + "\nIMPORTANT: ALWAYS adhere to this exact format for tool use:\n<｜tool▁calls▁begin｜><｜tool▁call▁begin｜>tool_call_name<｜tool▁sep｜>tool_call_arguments<｜tool▁call▁end｜>{{additional_tool_calls}}<｜tool▁calls▁end｜>\n\nWhere:\n\n- `tool_call_name` must be an exact match to one of the available tools\n- `tool_call_arguments` must be valid JSON that strictly follows the tool's Parameters Schema\n- For multiple tool calls, chain them directly without separators or spaces\n" %}
   {% set ns.system_prompt = ns.system_prompt + '\n\n' + tool_ns.text %}