agent-ready cannot pass anywhere: the checker-discovery loop always skips five arg-gated gates against the zero-skip READY contract

What

Since the preflight checker-discovery loop landed (d574f514a), every local python3 scripts/agent-ready.py fails on every host, for every branch, including a clean checkout of origin/main. The loop runs every scripts/check-*.py WITHOUT arguments; five checkers require them and always exit with argparse usage errors, which the loop reports as SKIP ("needs arguments preflight does not supply"):

• check-pr-size.py (--base/--head required)
• check-arm-isa-build.py, check-cpu-isa-build.py, check-cuda-fat-gencode.py (--compile-commands required)
• check-triton-aot-multiarch.py (--vendored-root required)

agent-ready.py invokes preflight with --fail-on-skip and refuses any skip — its documented #998 contract — so READY FAILED everywhere since the loop landed. Reproduce on origin/main 397a7c027: five SKIPs, READY FAILED.

Root cause

Two intended designs contradict:

1. The discovery loop's stated rule: "A checker that needs arguments this block cannot supply is a SKIP carrying the reason, never silence" — a skip is the HONEST report for an unrunnable gate.
2. agent-ready's #998 contract: the pre-handoff gate reads ANY skip as "not ready", because a skip once masked a trailer check that never ran.

Each is right alone; together they make READY unsatisfiable for every branch since the five checkers fell under the loop.

Candidate repairs (the fixing row decides with the developer)

• (a) Preflight constructs what it can and names what it cannot: run check-pr-size.py --base "$BASE_SHA" --head HEAD locally (always constructible); give the build-artifact gates explicit blocks that run when their input exists (compile_commands.json under build/, the vendored triton root) and skip naming the absent artifact when it does not. agent-ready's zero-skip contract stays intact; the skip population becomes genuinely host-conditional instead of unconditional.
• (b) agent-ready learns a stated tolerance class for artifact-gated skips. Weakens #998; needs the developer.
• (c) A combination.

Blocking

Every pre-push READY on every branch and host since d574f514a. Found pushing the tt_clock_state W2 row, which classified its gate run against this issue as the named blocker.

Owning row (candidate): CHECKER-READY-ARG-GATES.

Start with scripts/agent-ready.py and the preflight checker-discovery loop, reproducing the five SKIPs on origin/main at 397a7c027. Read the argument requirements in check-pr-size.py, check-arm-isa-build.py, check-cpu-isa-build.py, check-cuda-fat-gencode.py, and check-triton-aot-multiarch.py, then review the candidate repairs with the developer. Done means the chosen design resolves the unconditional skips without violating the documented READY contract.