I want a /write-mftf command — what should it know about my repo?

Three things, baked into the command body. (1) Where MFTF tests live in your repo — usually app/code/<Vendor>/<Module>/Test/Mftf/Test/<StoryName>Test.xml, but custom themes vary. (2) The command to run a single test: vendor/bin/mftf run <StoryName>. (3) The convention to extend Magento's built-in action groups, never write raw selectors. Sample body: "Generate an MFTF test for <arg>. Use only Magento_*, Hyva_*, or our existing action groups; do not introduce new page.xml selectors. Output the test file, then run it." Time to first green test: 5 minutes.