别只看模型跑分，这篇论文拆穿了端侧模型的电话代接短板，还附了踩坑评测方法，做手机智能体的值得读。
该研究提出CallScreenBench基准，用来评估手机端侧模型代接未知来电的表现。评测从五个质量维度打分，不合并为单一总分。研究用6个0.6B到4B参数的端侧模型，在4-bit量化下做测试，发现能力越高回答质量越好，但来电分流质量并不随之提升。修正脚本化退化基线后，11/15个模型对的分流差异在预注册操作点归零。一个只会挂断和复述对方的智能体也能拿到完美消息保真分数。
CallScreenBench: Benchmarking On-Device Models as Phone Secretaries
Language models small enough to run on a handset, quantized to a few bits, are increasingly capable of acting for their user, making on-device task automation newly plausible. One such task is answering the phone. A phone secretary takes an unknown inbound call on its owner's behalf. Unlike the agents evaluated by most benchmarks, it has no task to complete and no cooperative user: the caller holds the goal, may be an adversary, and must be judged from the opening turn with no oracle. What matters is not task success, but whether the owner would endorse how their proxy handled the call. We present CallScreenBench, which scores this setting on five quality dimensions. Each dimension is printed beside the counter-metric that bills it and is never averaged into a single number. We also report a guardedness profile for a toolless proxy that holds no credentials and calls no tools. Across six on-device models (0.6-4B parameters, 4-bit quantization), quality scales with capability, but triage does not. The appearance that it does is an artifact of measurement. Scripted degenerate agents supply the missing floors: after correcting for them, the number of model pairs whose triage performance separates falls from 11 of 15 to zero at the preregistered operating point. An agent that simply hangs up and echoes the caller also scores perfect message fidelity. We report which of our own metrics these floors defeat and declare no pass/fail threshold.