AI Papers of the Week
Every paper worth reading in AI, hand-picked one week at a time.

Structural Planning for LLM Agents
This paper introduces Routine, a structured planning format designed to improve the stability and accuracy of LLM agents executing multi-step tool-calling tasks in enterprise settings. Traditional agent planning approaches often fail in enterprise scenarios due to unstructured plans, weak instruction following, and tool selection errors. Routine addresses these by decomposing tasks into structured steps that include tool names, execution logic, and optional input/output specifications. The authors evaluate Routine on real-world HR scenarios and show strong performance gains in both open and fine-tuned models.

Inverse Scaling in Test-Time Compute
This paper presents a systematic study of inverse scaling in large reasoning models (LRMs), where increasing the test-time compute (i.e., reasoning length) harms rather than helps model performance. The authors introduce benchmark tasks across three categories: simple counting with distractors, regression with spurious features, and deductive logic puzzles, revealing consistent accuracy degradation as reasoning length increases. The work identifies model-specific failure modes and raises critical implications for LLM safety and alignment.

Towards Compute-Optimal Many-Shot In-Context Learning
Proposes practical strategies for reducing the cost of many-shot in-context learning while preserving or improving performance. With long-context LLMs like Gemini Pro and Flash supporting thousands of demonstrations, caching becomes essential, yet naïvely using only random demonstrations misses potential accuracy gains from smarter selection.

Deep Researcher with Test-Time Diffusion
Rethinks how deep research agents generate long-form reports. Rather than relying on static inference strategies like Chain-of-Thought or best-of-n sampling, TTD-DR frames the report generation process as a diffusion process. It starts with a noisy draft and iteratively refines it through retrieval-enhanced denoising, guided by a structured plan. This iterative loop mimics how human researchers search, reason, revise, and accumulate context over time.

MCPEval
MCPEval is an open-source framework that automates end-to-end evaluation of LLM agents using a standardized Model Context Protocol, eliminating manual benchmarking. It supports diverse domains, integrates with native tools, and reveals nuanced performance through domain-specific metrics.

One Token to Fool LLM-as-a-Judge
Investigates the surprising fragility of LLM-based reward models used in Reinforcement Learning with Verifiable Rewards (RLVR). The authors find that inserting superficial, semantically empty tokens, like “Thought process:”, “Solution”, or even just a colon “:”, can consistently trick models into giving false positive rewards, regardless of the actual correctness of the response.

Context Rot
This comprehensive study by Chroma evaluates how state-of-the-art LLMs perform as input context length increases, challenging the common assumption that longer contexts are uniformly handled. Testing 18 top models (including GPT-4.1, Claude 4, Gemini 2.5, Qwen3), the authors demonstrate that model reliability degrades non-uniformly even on simple tasks as input grows, what they term "context rot."

Agentic-R1
This paper introduces Agentic-R1, a 7B language model trained to dynamically switch between tool-based execution and pure text reasoning using a novel fine-tuning framework called DualDistill. Rather than relying solely on long chain-of-thought (long-CoT) reasoning or tool use, the method composes solution trajectories from two specialized teachers, one strong in abstract reasoning (Deepseek-R1) and another in code-based tool use (OpenHands/Claude-3.5). The student learns to select the best strategy per task and improves further via self-distillation.

Chain-of-Thought Monitorability
Proposes that language-based CoT reasoning in LLMs offers an opportunity for AI safety by enabling automated oversight of models’ internal reasoning processes. The authors argue that, while imperfect, CoT monitoring is a promising method for detecting misbehavior, revealing goals, and improving interpretability, but its effectiveness is fragile and must be preserved with care.

Stress Testing Large Reasoning Models
Proposes a new benchmark framework called REST to evaluate the robustness of Large Reasoning Models (LRMs) under multi-question stress. Unlike traditional single-question evaluations, REST tests models by presenting multiple reasoning problems in a single prompt, better simulating real-world multi-tasking demands.

Machine Bullshit
This paper introduces the concept of machine bullshit, extending Harry Frankfurt’s definition, discourse made with indifference to truth, to LLMs. The authors formalize this behavior with a new quantitative metric (the Bullshit Index) and a four-part taxonomy (empty rhetoric, paltering, weasel words, unverified claims). Their findings reveal that alignment techniques like RLHF and prompting strategies like CoT can systematically increase deceptive or misleading outputs in LLMs.

A Survey of AIOps
This survey analyzes 183 papers to evaluate how LLMs are being used in AIOps, focusing on data sources, task evolution, applied methods, and evaluation practices. It identifies key trends, research gaps, and outlines future directions for LLM-powered AIOps systems.

Kimi K2
Moonshot AI introduces Kimi K2, a 1T parameter Mixture-of-Experts model (32B active) optimized not just for knowledge tasks but for agentic capabilities, models that act, not just respond. Released as Kimi-K2-Base and Kimi-K2-Instruct, it achieves strong scores across coding, math, and tool-use benchmarks and is open-source for research and deployment.

MemAgent
Introduces an RL–driven memory agent that enables transformer-based LLMs to handle documents up to 3.5 million tokens with near lossless performance, linear complexity, and no need for architectural modifications.

AI Research Agents for Machine Learning
Presents a new framework, AIRA-dojo, for developing and evaluating AI research agents. They use this framework to systematically investigate the components of successful AI agents on the MLE-bench benchmark, a challenging set of real-world machine learning problems from Kaggle. Key findings:

Adaptive Branching MCTS
Researchers from Sakana AI introduce Adaptive Branching Monte Carlo Tree Search (AB-MCTS), a new framework that dynamically decides whether to "go wider" (explore new solutions) or "go deeper" (refine existing ones) during inference. Key ideas:

AI4Research
This survey offers the first unified and comprehensive framework for understanding how AI is transforming the full lifecycle of scientific research. The paper identifies five core areas: Scientific Comprehension, Academic Survey, Scientific Discovery, Academic Writing, and Academic Peer Review, and presents a detailed taxonomy and modeling approach for each.

Threats in LLM-Powered AI Agents Workflows
This work presents the first comprehensive, end-to-end threat model for LLM-powered agent ecosystems. As LLM agents gain the ability to orchestrate multi-step workflows and interact via protocols like MCP, ANP, and A2A, this paper surveys over 30 attack techniques spanning the entire stack, from input manipulation to inter-agent protocol exploits.

Deep Research Agents
Provides the most comprehensive survey to date of Deep Research (DR) agents, LLM-powered systems built for autonomous, multi-step informational research. The paper defines DR agents as AI systems that tightly integrate dynamic reasoning, adaptive long-horizon planning, tool use, retrieval, and structured report generation. It establishes a taxonomy of DR architectures, evaluates recent advances, and outlines the limitations of current systems and benchmarks.

Survey on Evaluation of LLM-based Agents
This work presents the first comprehensive overview of how to evaluate LLM-based agents, which differ significantly from traditional LLMs by maintaining memory, planning over multiple steps, using tools, and interacting with dynamic environments. The authors categorize and analyze the evaluation landscape across four axes: core agent capabilities, application-specific agent benchmarks, generalist agent evaluation, and supporting evaluation frameworks.

Ultra-Fast Diffusion-based Language Models
This paper introduces Mercury, a family of large-scale diffusion-based language models (dLLMs) optimized for ultra-fast inference. Unlike standard autoregressive LLMs, Mercury models generate multiple tokens in parallel via a coarse-to-fine refinement process. This approach enables significantly higher throughput without sacrificing output quality. The initial release focuses on code generation, with Mercury Coder Mini and Small models achieving up to 1109 and 737 tokens/sec, respectively, on NVIDIA H100s, outperforming speed-optimized frontier models by up to 10× while matching or exceeding their quality.

MEM1
This work introduces MEM1, an RL framework for training language agents that operate efficiently over long-horizon, multi-turn tasks by learning to consolidate memory and reasoning into a compact internal state. Unlike traditional agents that append all past interactions, leading to ballooning memory usage and degraded performance, MEM1 maintains a constant memory size by discarding obsolete context after each reasoning step. It achieves this by jointly updating an internal state that encodes both new observations and prior memory, optimizing for task completion via RL without needing external memory modules. Key contributions and findings:

Towards AI Search Paradigm
Proposes a modular multi-agent system that reimagines how AI handles complex search tasks, aiming to emulate human-like reasoning and information synthesis. The system comprises four specialized LLM-powered agents, Master, Planner, Executor, and Writer, that dynamically coordinate to decompose, solve, and answer user queries. This framework moves beyond traditional document retrieval or RAG pipelines by structuring tasks into directed acyclic graphs (DAGs), invoking external tools, and supporting dynamic re-planning. Key contributions include:

Reinforcement-Learned Teachers of Test Time Scaling
Introduces Reinforcement-Learned Teachers (RLTs), small, efficient LMs trained with RL not to solve problems from scratch, but to generate high-quality explanations that help downstream student models learn better. This approach circumvents the notorious exploration challenges in traditional RL setups by giving the RLTs access to both questions and solutions, thereby framing the task as “connect-the-dots” explanation generation. These explanations are rewarded based on how well a student LM, trained on them, understands and can reproduce the correct answer, enabling dense, interpretable supervision. Key contributions and findings: