OpenAI's testing found very high error rates in the MCP connectors it evaluated.

“On paper it looks bad. It's like you can... They might already have a license for it, so they might feel like they're paying twice for it. Um, and they might have an MCP. And so, like, why are you building this? And the reality is, we went and we tested all these MCPs, and what we found was the error rates were, were really, really high.”