Tool-Use

TL;DR MCP‑AgentBench is the first broad benchmark that evaluates language agents inside the Model Context Protocol (MCP) rather than with ad‑hoc function calls. It sets up 33 MCP servers with 188 tools and runs 600 goal‑oriented queries across six task patterns. Results flip a few assumptions: open‑source leaders (notably Qwen3‑235B‑A22B) can top the table under the ReAct style, while Claude 4 Sonnet shines with native tool‑calling. Token budgets matter: o3‑mini posts the best performance‑per‑token among big names. The meta‑lesson for builders: your agent’s interaction style must match the model and benchmarks must reward outcome, not ritual. ...

Large language models are finally learning to work the tools instead of merely talking about them. RLFactory proposes a clean way to post‑train LLMs for multi‑turn tool use by rebuilding the reinforcement learning loop around tool feedback, not just text. The result: quicker training, higher stability, and a framework teams can actually adopt. Why this matters (and where prior setups struggle) Most RL-for-LLMs treat the environment as pure text: the model thinks, emits tokens, gets a scalar reward. But real tasks—searching, querying databases, compiling code, booking travel—depend on external tools that return structured results, fail intermittently, and vary in latency and format. Hard problems emerge: ...

How a new survey formalizes the shift from RLHF’d text bots to tool-using operators—and the practical playbook for product teams. TL;DR Agentic RL reframes LLMs from one-shot text generators to policies acting in dynamic environments with planning, tool use, memory, and reflection. The paper contrasts PBRFT (preference-based RL fine-tuning) with Agentic RL via an MDP→POMDP upgrade; action space now includes text + structured actions. It organizes the space by capabilities (planning, tools, memory, self-improvement, reasoning, perception) and tasks (search, code, math, GUI, vision, embodied, multi-agent). Open challenges: trust, scalable training, and scalable environments. For builders: start with short-horizon agents (verifiable rewards), invest early in evaluation, and plan a migration path from RAG pipelines to tool-integrated reasoning (TIR) with RL. What the paper actually changes Most “LLM RL” work you’ve seen is PBRFT—optimize responses to fit human/AI preferences (RLHF/DPO/etc.). This new survey argues that real autonomy needs Agentic RL: treat the model as a policy embedded in a sequential, partially observable world. That sounds academic, but the practical consequences are huge: ...

TL;DR Most “tool‑using” LLMs still practice in sterile gyms. MUA‑RL moves training into the messy real world by adding an LLM‑simulated user inside the RL rollout, wiring the agent to call actual tools and rewarding it only when the end task is truly done. The result: smaller open models close in on or beat bigger names on multi‑turn benchmarks, while learning crisper, policy‑compliant dialogue habits. Why this matters now Enterprises don’t want chatty copilots; they want agents that finish jobs: modify an order under policy, update a ticket with verified fields, push a fix to a repo, or reconcile an invoice—often across several conversational turns and multiple tools. Supervised fine‑tuning on synthetic traces helps, but it often overfits to static scripts and misses the live back‑and‑forth where users change their minds, add constraints, or misunderstand policy. ...

Most “agent” decks promise autonomy; few explain how to make it shippable. A new survey of LLM‑based agentic reasoning frameworks cuts through the noise with a three‑layer taxonomy—single‑agent methods, tool‑based methods, and multi‑agent methods. Below, we translate that map into a practical build/run playbook for teams deploying AI automation in real workflows. TL;DR Single‑agent = shape the model’s thinking loop (roles, task prompts, reflection, iterative refinement). Tool‑based = widen the model’s action space (APIs, plugins/RAG, middleware; plus selection and orchestration patterns: sequential, parallel, iterative). Multi‑agent = scale division of labor (centralized, decentralized, or hierarchical; with cooperation, competition, negotiation). Treat these as orthogonal dials you tune per use‑case; don’t jump to multi‑agent if a reflective single agent with a code‑interpreter suffices. 1) What’s genuinely new (and useful) here Most prior surveys were model‑centric (how to finetune or RLHF your way to better agents). This survey is framework‑centric: it formalizes the reasoning process—context $C$, action space $A = {a_{reason}, a_{tool}, a_{reflect}}$, termination $Q$—and shows where each method plugs into the loop. That formalism matters for operators: it’s the difference between “let’s try AutoGen” and “we know which knob to turn when the agent stalls, loops, or hallucinates.” ...

Thesis: AgentScope 1.0 is less a toolkit and more a discipline for agentic software. By pinning everything to ReAct loops, unifying “message–model–memory–tool,” and adding group-wise tool provisioning, it addresses the real failure mode of agents in production: tool sprawl without control. The evaluation/Studio/runtime trio then turns prototypes into shippable services. What’s actually new (and why it matters) 1) A crisp core: Message → Model → Memory → Tool Most frameworks blur these into ad‑hoc objects; AgentScope forces a clean, composable boundary: ...

The pitch: a unified plug—and a tougher test The Model Context Protocol (MCP) is often described as the “USB‑C of AI tools”: one standardized way for agents to talk to external services (maps, finance data, browsers, repos, etc.). MCP‑Universe, a new benchmark from Salesforce AI Research, finally stress‑tests that idea with real MCP servers rather than toy mocks. It derives success from execution outcomes, not multiple‑choice guesswork—exactly what enterprises need to trust automation. ...

In early 2025, Apple’s now-infamous “thinking-illusion” benchmark delivered a sobering verdict: large reasoning models (LRMs)—those step-by-step thinkers like DeepSeek-R1 and Qwen 3 Thinking—failed to show meaningful advantages over simpler LLMs. Their verbose, reflective outputs didn’t help on easy problems, nor did they scale on hard ones. In some cases, they even underperformed. But what if we were judging thinking models under unfair conditions? A new study titled “Thinking Isn’t an Illusion” argues that the problem isn’t with reasoning itself—it’s with reasoning in a vacuum. When these models are augmented with tools like Python interpreters and structured scratchpads, their performance transforms dramatically. In fact, they begin to consistently outperform their non-reasoning counterparts across a diverse set of logic puzzles. ...

As LLM-powered agents become the backbone of many automation systems, their ability to reliably invoke external tools is now under the spotlight. Despite impressive multi-step reasoning, many such agents crumble in practice—not because they can’t plan, but because they can’t parse. One wrong parameter, one mismatched data type, and the whole chain collapses. A new paper titled “Butterfly Effects in Toolchains” offers the first systematic taxonomy of these failures, exposing how parameter-filling errors propagate through tool-invoking agents. The findings aren’t just technical quirks—they speak to deep flaws in how current LLM systems are evaluated, built, and safeguarded. ...

If ReAct was a spark, Pre-Act is a blueprint. In the paper Pre-Act: Multi-Step Planning and Reasoning Improves Acting in LLM Agents, Mrinal Rawat et al. challenge the single-step cognitive paradigm of ReAct, offering instead a roadmap for how agents should plan, reason, and act—especially when tool use and workflow coherence matter. What Is ReAct? A Quick Primer The ReAct framework—short for Reasoning and Acting—is a prompting strategy that allows an LLM to alternate between thinking and doing in a loop. Each iteration follows this pattern: ...