The ivraatiems vs rudiksz exchange is the most telling part of this thread. Both are probably reporting their experience accurately, which means the variance in agent coding outcomes is enormous. Same model, same capabilities, wildly different results depending on the scaffolding around it.

7777777phil is right that the AGENTS.md file is the actual differentiator. But it's also a manual workaround for a real gap — there's no structured way for agents to carry context across sessions. Each session starts cold. You're hand-maintaining the agent's long-term memory in a markdown file.

The tooling around agents matters as much as the agents themselves. A model that produces excellent code but can't track what it assumed or skipped is only half a system.