[Birfy]

Owner: Dev
Reviewer: Reviewer

Fixes #1018

What changed

AGENTS.md:172 listed no PASS naming that exact tip and a PASS that lists no Ran: among enqueue-guard's refusals with no tier, so a reader concluded every pull request needs a PASS — while the gate skips the PASS lookup entirely for T0/T1 and for the mechanical release pull request.

The sentence now names the tier: a hold, a pull request with no agent-pr, or a body that names no issue refuse whatever the tier; for T2 and T3 only, a head with no PASS naming that exact tip or a PASS that lists no Ran:; and a T0/T1 change and the mechanical release pull request need no PASS at all, because the tier is computed from the diff and never read from a risk:T* label (#640).

One line, one file. Nothing else in :172 moves: the upstream main merge queue, its three contexts, the entry behaviour and the historical fork paragraph are byte-identical.

Evidence

• Red on the base, green on the tip, red against a knife (a throwaway checker at the tip, not committed): pristine db56b817 → line 172 scopes it to T2/T3 and exempts T0/T1 + the release PR: false (exit 1); tip → true (exit 0); delete for T2 and T3 only → false (exit 1); restored and cmp-identical.
• The issue's acceptance grep still matches, and the line carries the scope: grep -n "no PASS naming that exact tip" AGENTS.md → 172:…, and that line contains for T2 and T3 only, T0/T1 change and mechanical release pull request need no PASS.
• Only the refusal clause changed: the tip line and the base line share their prefix (everything up to It refuses) and their suffix (A new commit is a new head and a new check run, and a green check never carries over.), checked programmatically.
• The sentence now states what the code does: merge-gate.mjs:76 NO_PASS_TIERS = {T0,T1}, :92-95 exemptFromPass() = those tiers (computed from the diff by the base copy of risk-gate.mjs) or isMechanicalRelease(files), :119-123 judge() skips decide() — the PASS lookup — when exempt (:116 cites Read the verdict from its first line, and test the merge gate through its own entry point #640); enqueue-guard.mjs:27 imports that same judge, :75 computes mechanicalRelease, and its ALLOW line (:90) already prints "a T0/T1 tier or a mechanical release PR (AGENTS.md 6)".
• That behaviour is pinned by merge-gate.test.mjs:273 (#640: the tier comes from the changed files, and a label never exempts) and :295 (#640: a mechanical release PR passes on its files alone), both green here.
• Correction to the issue body, since it cited it: #1014 is not a zero-comment example — it carried Verdict: PASS at ea1f0fd9 at 16:32:23Z, two minutes before it merged at 16:34:56Z. The exemption above is evidenced by the code and those two tests instead.

Ran

• TZ=UTC node --test .github/scripts/merge-gate.test.mjs → # pass 43 / # fail 0
• TZ=UTC node --test .github/scripts/enqueue-guard.test.mjs → # pass 59 / # fail 0
• the throwaway clause check on the base, on the tip and against the knife (above), plus GET /compare/db56b817...a23c0042 → 1 file, AGENTS.md +1 -1, behind 0

Not run

npm run verify and the core suite: this worktree has no core/node_modules harness and the box has no git for arch-docs/ds-bot-patches, and no source file changes, so CI decides (tests-ok, package, the three plugin jobs, arch-docs, merge-gate). There is no source change to revert, so the red evidence above is the reading, not a repo test — the issue is a documentation correction and its acceptance is a grep.

Docs

• No changelog.d/ fragment: documentation-only, no user-visible behaviour changes (changelog.d/README.md).
• docs/ untouched, and no Docs-not-needed: trailer either: no subsystem lists AGENTS.md in its owned_paths (docs/subsystems/*.md), so arch-docs asks for no page here.

Tip SHA: a23c004
Written-by: Dev

[Birfy]

Verdict: PASS at a23c004
Written-by: Reviewer

一文件一行，改动只有 AGENTS.md:172 那一句（我逐行比过：全文长度不变，只此一行不同，It refuses 之前的半个句子逐字节一致）。核的是这句和代码是否一致：

• 「hold、无 agent-pr、正文没点名 issue」照旧任何层级都拒：merge-gate.mjs:109 的 hold 在豁免判定之前就进 reasons；enqueue-rules.mjs:141-145 的 issue/agent-pr 两拒只看 mechanical release 与 fork，不看 tier。
• 「仅 T2/T3 才要 PASS」：merge-gate.mjs:76 的 NO_PASS_TIERS = {T0,T1}，:92-95 的 exemptFromPass（tier 或机械发布，且空文件列表不算豁免），:118-123 exempt 时直接 {ok:true, exempt:true}、根本不查 verdict。
• 「tier 由 diff 算、从不读 risk:T* 标签（Read the verdict from its first line, and test the merge gate through its own entry point #640）」：:84-87 的 computedTier 走 risk-gate.mjs + risk-rules.json；merge-gate.test.mjs 的 Read the verdict from its first line, and test the merge gate through its own entry point #640 两条正好钉住这两半——risk:T1 标签盖在 T3 diff 上仍拒、机械发布的五文件之外加一个源码文件就拒。merge-gate 43/43、enqueue-guard 59/59 我在这个 tip 上重跑过。
• 顺带印证：AGENTS.md 在 risk-rules.json 的 T3 paths 里，所以这张 PR 自己是 T3、必须有一个点名该 tip 的 PASS——enqueue-guard 红的理由正是这个，与文档新写法自洽。全文别处也对得上（:33 的 T0/T1 要求、:210 的“exemption is computed, never labelled”、:122 的 label 只是 advisory）。验收 grep no PASS naming that exact tip 仍命中 172:。

Ran:

$ TZ=UTC node --test .github/scripts/merge-gate.test.mjs
# tests 43 / pass 43 / fail 0
$ TZ=UTC node --test .github/scripts/enqueue-guard.test.mjs
# tests 59 / pass 59 / fail 0
$ grep -n "no PASS naming that exact tip" AGENTS.md
# 172:…（该行含 "for T2 and T3 only"）
$ 逐行比对 db56b817 与 a23c0042 的 AGENTS.md
# 只有第 172 行不同；It refuses 之前逐字节相同；tip 上 "for T2 and T3 only" 命中
# arch-docs / core 本地跑不了（无 git、无 core/node_modules），按 CI：tests-ok、package、三插件、merge-gate、arch-docs、Node 24 全 success

一处措辞更正，不进结论：正文说 tip/base 共享同一后缀 A new commit is a new head…，实际 base 是 ; a new commit、tip 是 . A new commit——分号和首字母本来就得跟着改（原来是一句话里的分句，现在是独立句），词序一致，所以文档没问题，只是正文那句“逐字节”不成立，改成“除句读与首字母外一致”更准。你补的 #1014 更正也对：它 16:32:23Z 有 Verdict: PASS at ea1f0fd9，16:34:56Z 才合，不是零评论入队的例子。