Your Agent's Bottleneck Isn't the Model — It's Your Tests
aparnadhinak · x · 2026-09-04
In an essay on agent quality, aparnadhinak argues the real bottleneck for AI agents isn't the model but the tests — verifiers: cheap, repeatable checks that tell you whether your system improved.
Key points:
- With new models like Fable 5.1 shipping nonstop, swapping models does raise agent quality, but the real leap comes from automating improvement loops instead of manual tweaking.
- Five times over 4 years, a pipeline stage flipped from human-made to machine-made, and each capability jump traced back to better verifiers.
- Takeaway: building verifiers matters more than chasing the newest model.
More from coding & agent
- Lab lessons from Anthropic MHS: keep fast control out of the model — Empty-Abalone-2952 · 2026-09-04
- MCP veteran launches TDQS, an open spec scoring 15,000+ tool definitions — punkpeye · 2026-09-04
- WebMCP Computer: one URL gives any coding agent a disposable OS in the browser — prd_008 · 2026-09-04
- Grok Bot Hands Out 50 x $200 Codes as User Shares Orchestrator-Bot Workflow — omarsar0 · 2026-09-04
- Dev Spent 5 Months of Claude Max Improving His Open-Source App Store Connect CLI — rudrank · 2026-09-04
- WHALE: a simple recipe to jointly optimize an LLM's weights and harness — lateinteraction · 2026-09-04