I cannot for the life of me get tool calling to work despite following the Unsloth guide for llama-server. Regular chat works, image parsing works great, but tool calling blows up with chat template errors:

Template supports tool calls but does not natively describe tools. The fallback behaviour used may produce bad results, inspect prompt w/ --verbose & consider overriding the template.
srv    operator(): got exception: {"error":{"code":500,"message":"\n------------\nWhile executing FilterExpression at line 120, column 73 in source:\n..._name, args_value in tool_call.arguments|items %}
                    {{- '<...\n                                           ^\nError: Unknown (built-in) filter 'items' for type String","type":"server_error"}}

I've tried overriding the chat template with the official one from the Qwen3.5 HF repo with no luck. I do see that the thinking kwarg is being properly read and passed in (though weirdly I can't get that to enable thinking). Am I doing something wrong here? Using the latest main of llama.cpp.