behavioral-gradient validator

OverEager-Bench: Measuring Out-of-Scope Actions by Coding Agents on Benign Tasks

This paper introduces OverEager-Gen/Bench, a 500-scenario benchmark measuring 'overeager' behavior in coding agents—cases where agents with shell, file, and network access take unauthorized actions beyond the user's stated request on benign tasks. The study reveals a critical measurement-validity issue: explicitly declaring authorized scope in prompts suppresses overeager behavior (e.g., Claude Code drops from 17.1% to 0.0%), so the benchmark uses consent-stripped variants to expose true agent tendencies. Across four agent products (Claude Code, OpenHands, Codex CLI, Gemini CLI) and six base models, framework architecture dominates effect size: permissive frameworks run at 5.4–27.7% overeager rates while OpenHands' ask-to-continue design sits at 0.2–4.5%. Within-framework base-model variance of up to 15.9 pp indicates that model-level alignment does not fully propagate through permissive permission gating.