Anthropic Says Use More Agents to Fix Agent Code. Here's What's Missing.

Last week, Anthropic published their recommended architecture for building production apps with Claude Code. The core idea: a multi-agent harness where a Planner expands prompts into specs, a Generator implements features, and an Evaluator grades output against criteria. It's a solid pattern inspired by GANs - one system creates, another critiques, and the tension drives quality up. But there's a gap nobody seems to be talking about. The Shared Blind Spot Problem When your Generator is Claude and your Evaluator is also Claude, they share the same training data, the same biases, and the same blind spots. It's like asking your coworker to proofread something they helped you write. They'll catch typos. But the structural problems - the wrong assumptions, the edge cases neither of you considered - those survive because you both have the same mental model of what "correct" looks like. We've seen this play out: Auth flows that passed evaluation but used client-side token storage with no expi