Procedural Authority in Language Agents: Isolating the Behavioral Effect of Skills Beyond Their Information Content

Large language model agents increasingly rely on framework-loaded Skills that package procedural knowledge for multi-step tool use. These Skills can improve execution efficiency, but their recognized status can also affect whether agents verify instructions, revise plans after conflicting observations, or commit to consequential state changes. Isolating this effect requires Skill-based and ordinary-context conditions to match in content, authority cues, formatting, placement, and computational resources. We define the Procedural Authority Effect as the behavioral change induced by representing fixed procedural knowledge as a named, scope-declared Skill compared with semantically matched ordinary context. We introduce Paired Procedural-Authority Trial with Provenance-Gated Verification (PAT-PV), a causal evaluation framework that crosses procedural identity with content quality, source labeling, surface format, and counterevidence strength while controlling task state, tool permissions, token budget, and computation. PAT-PV evaluates observable agent trajectories using erroneous-action adoption, independent evidence acquisition, plan revision after decisive counterevidence, post-error recovery, and terminal success. Its provenance-gated verification mechanism exposes a relevant read-only check before unsupported Skill-dependent state changes without providing an oracle judgment. We instantiate PAT-PV in isolated stateful sandboxes covering file management, scheduling, inventory workflows, and code configuration. The evaluation uses paired randomization, repeated decoding, semantically equivalent templates, and matched baselines. This design supports controlled analysis of how framework-recognized procedural identity affects the efficiency and reliability of tool-using agents.