Today's pick
Specification Grounding Drives Test Effectiveness for LLM Code
+38pp
final code correctness, every tier tested
One prompt line — hand the LLM test-writer the spec as an explicit rule checklist — lifts final code correctness +38pp over an equally-budgeted edge-prompted baseline, replicated cross-vendor (GPT +28, Gemini +19). Doubling the test budget or ensembling 8 ungrounded suites barely moves; grounded tests recover 27/30 bugs vs 2/30 and cut false rejections of correct code from 33% to 0%.
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Think Big, Search Small: Where Capacity Matters in Hierarchical Search Agents?
+11 EM
from scaling the planner — executor scaling adds just +2.6
Controlled capacity sweeps show decomposition is the bottleneck in hierarchical search agents: spend your biggest model on planning and run retrieval and extraction sub-agents on cheap small ones — a distilled 1.7B executor matches a frontier sub-agent with 37% fewer sub-agent tokens.
Reason Less, Verify More: Deterministic Gates Recover a Silent Policy-Violation Failure Mode in Tool-Using LLM Agents
+12.4pp
task success from deterministic pre-write gates
78% of tau2-bench airline failures were silent policy-violating writes with no tool error; deterministic validators that check each proposed write against current state lift gpt-4o-mini success from 29.6% to 42.0% with no model changes. Gates add little where tools already enforce policy.
Progressive Crystallization: Turning Agent Exploration into Deterministic, Lower-Cost Workflows in Production
>70%
per-incident agent cost cut in production
Promote repeatedly-validated agent traces into deterministic workflows and auto-demote on regression: a production AIOps system went from 0% to 45% deterministic execution in 8 months while volume doubled, and the paper supplies the promotion criteria, trace-extraction method, and economic model.
From Noisy Traces to Root Causes: Structural Trajectory Analysis and Causal Extraction for Agent Optimization
1.4×
agent success from de-noised failure traces
STRACE clusters redundant failure traces and prunes non-causal steps via a dependency graph before the LLM optimizer sees them, lifting success from 42.5% to 58.5% on VeruSAGE-Bench — a copyable recipe for any trace-driven agent-improvement loop.
From Atomic Actions to Standard Operating Procedures: Iterative Tool Optimization for Self-Evolving LLM Agents
EvoSOP mines recurring multi-step workflows from agent traces and registers them as composite tools, with a construct, merge, evaluate, prune lifecycle that keeps a growing toolset from bloating context. The abstract claims higher success and fewer rounds but reports no figures, and there is no code.
The Blind Curator: How a Biased Judge Silently Disables Skill Retirement in Self-Evolving Agents
False-pass bias in an LLM judge silently disables skill retirement past a sharp threshold no data volume can cross, while symmetric noise is harmless. Before trusting any judge-gated loop, inject known-bad outputs and measure the judge's false-pass rate.