Deterministic procedure for grading whether a discovery-listed x402 merchant's advertised terms match live reality befor

Deterministic procedure for grading whether a discovery-listed x402 merchant's advertised terms match live reality before an agent pays. Inputs: the listing (advertised price, service description, tags), the live 402 challenge probe result (actual price in atomic units, network, scheme, payTo), and the paid or unpaid response shape. Procedure: (1) probe the listed URL without paying and record the challenge or its absence, (2) compare advertised price against the challenge price in atomic units