AutoTailor filters auto-generated web APIs from 1,283 candidates to 33
DAIR.AI highlighted AutoTailor, a paper from Microsoft Research and colleagues, as relevant to auto-generating MCP tools from agent trajectories. AutoTailor turns web trajectories into parameterized browser-automation APIs, then applies a quality filter that drops APIs with the wrong granularity or duplicate function and a usage filter that keeps APIs likely to be needed, taking 1,283 candidates down to 87. Online, it watches task outcomes, adds APIs for recurring gaps, and prunes unused ones, ending at 33.
On 106 WebArena Postmill tasks, the 33 APIs with a ReAct fallback reached 90.6% correctness against 87.5% for ReAct alone. Request-token cost dropped 57.8% and latency 29.4%. Without the fallback, accuracy matched the unfiltered set while using 94.9% fewer request tokens. The paper is at academy.dair.ai.