diff --git a/docs/architecture/RESILIENCE_GUIDE.md b/docs/architecture/RESILIENCE_GUIDE.md
index 5aaba73652..98629da7db 100644
--- a/docs/architecture/RESILIENCE_GUIDE.md
+++ b/docs/architecture/RESILIENCE_GUIDE.md
@@ -318,14 +318,44 @@ excludeMarkers, defaultRetryAfterMs}`), matched via `applyStatusRestatement()`.
 - Retry eligibility: `429` is in `RETRY_AFTER_ELIGIBLE_STATUSES`
   (`open-sse/services/combo/unavailableRetryGate.ts`), so a restated error
   carries a real retry window instead of surfacing as a dead `403`.
+- The synthetic `60s` `defaultRetryAfterMs` (`upstreamStatusRestatement.ts`)
+  is only what the restated response tells the **client**; it is not itself
+  the connection's internal cooldown/lockout duration — that is governed
+  separately by whichever mechanism actually handles the restated error
+  (Connection Cooldown's escalating backoff, §2, base `3s` for API-key
+  providers; or Model Lockout, §3, for per-model-quota providers like
+  agentrouter). The router can become eligible to retry internally sooner
+  than the 60s window it advertises to the client — intentional headroom,
+  not a bug.
 
 Permanent errors (agentrouter's `无权访问模型` — no access to this model) are
 NEVER restated: `excludeMarkers` vetoes the rule even when `textMarkers` hit,
 so the error keeps its original status and nothing retries it forever. A
 separate provider classification rule
 (`agentrouter-model-access-denied` in `open-sse/config/providerErrorRules.ts`)
-locks only the affected model instead (Model Lockout, §3), so the connection
-keeps serving other models.
+declares an `auth_error`/scope-`model` match for this text, but it does not
+fire on the live production path today: the rule only matches `status ===
+403`, and `checkFallbackError`'s apikey-category `FORBIDDEN` branch
+(`open-sse/services/accountFallback.ts`) returns early for a plain 403
+*before* the provider-rule lookup ever runs. In practice a `无权访问模型` 403
+is handled the same way as the base apikey-provider 403 path (see Connection
+Cooldown, §2), not as a 6h model lockout. The rule still exists as a
+declarative classification consumable by future callers of `classifyError`
+with context — wiring it into the production `checkFallbackError` path is
+tracked as a follow-up, not yet done.
+
+Restated quota errors (`额度不足`) do reach a provider rule in production
+(`agentrouter-user-quota-exhausted`, scope `"connection"`), but `scope` on
+`ProviderErrorRuleMatch` is currently informational — the persistence path
+(`checkFallbackError` → `combo.ts`) only consumes `reason` and `cooldownMs`,
+never `scope`. What actually happens for agentrouter (`passthroughModels:
+true` → `hasPerModelQuota()` returns `true`) is a **per-model** lockout via
+`recordModelLockoutFailure()`: the connection itself is never cooled down for
+this error (`combo.ts` skips `recordProviderCooldown` for 429 when
+`hasPerModelQuota` is true), so other models on the same account keep being
+tried — each one burns one call and its own lockout before combo routing
+moves on. Honoring `scope` end-to-end (so a `"connection"` match actually
+locks the connection) is tracked as a follow-up.
 
 ### Two-stage design: status restatement, then classification
 
diff --git a/open-sse/config/providerErrorRules.ts b/open-sse/config/providerErrorRules.ts
index ae2f495573..dd59e991bc 100644
--- a/open-sse/config/providerErrorRules.ts
+++ b/open-sse/config/providerErrorRules.ts
@@ -29,7 +29,15 @@ export type ProviderErrorRule = {
 
 export type ProviderErrorRuleMatch = {
   reason: ConfiguredErrorReason;
-  /** Default "provider" — lock the whole connection so other providers take over. */
+  /**
+   * Intended lock scope. NOTE: this field is currently INFORMATIONAL — no
+   * consumer of `getProviderErrorRuleMatch` (checkFallbackError, combo.ts)
+   * reads `scope` today; only `reason` and `cooldownMs` are consulted. The
+   * actual lock scope applied at runtime is decided independently by each
+   * call site (e.g. `hasPerModelQuota()` deciding model- vs connection-level
+   * lockout). Honoring this field end-to-end is tracked as a follow-up —
+   * see `docs/architecture/RESILIENCE_GUIDE.md` §7.
+   */
   scope: "model" | "provider" | "connection";
   /** Optional explicit cooldown; falls back to the existing per-reason defaults. */
   cooldownMs?: number;
@@ -189,8 +197,22 @@ function buildOpenrouterRules(): ProviderErrorRule[] {
 // hands these rules the full error text instead of just {code, type}.
 //  - "额度不足": account-wide temporary quota → quota_exhausted, scope
 //    "connection" (mirror of the Opencode account-wide rationale above).
-//  - "无权访问模型": this key permanently lacks access to ONE model → lock only
-//    the model so the connection keeps serving the rest (Model Lockout tier).
+//    NOTE: `scope` on ProviderErrorRuleMatch is currently informational —
+//    checkFallbackError/combo.ts only consume `reason` and `cooldownMs`, not
+//    `scope`. For agentrouter specifically (passthroughModels: true →
+//    hasPerModelQuota() is true), this quota_exhausted match actually
+//    resolves to a PER-MODEL lockout (recordModelLockoutFailure), not a
+//    connection-wide lock — other models on the same account keep being
+//    tried by combo routing (each burning one call) until they lock out
+//    individually. Honoring `scope` end-to-end is tracked as a follow-up.
+//  - "无权访问模型": declares auth_error/scope "model" (intent: lock only the
+//    model so the connection keeps serving the rest — Model Lockout tier).
+//    This rule does NOT fire on the production path today: it only matches
+//    `status === 403`, but checkFallbackError's apikey FORBIDDEN branch
+//    returns early for a plain 403 before this rule is ever consulted (see
+//    the note above). A live `无权访问模型` 403 is handled like the base
+//    apikey-provider 403 today. Wiring this rule into that path is tracked
+//    as a follow-up.
 function buildAgentrouterRules(): ProviderErrorRule[] {
   const AGENTROUTER_ERROR_STATUSES = new Set([400, 403, 429]);
   return [
diff --git a/open-sse/config/upstreamStatusRestatement.ts b/open-sse/config/upstreamStatusRestatement.ts
index 75f84ecf72..ccadf2d704 100644
--- a/open-sse/config/upstreamStatusRestatement.ts
+++ b/open-sse/config/upstreamStatusRestatement.ts
@@ -29,6 +29,14 @@
  * "insufficient_quota" are in CREDITS_EXHAUSTED_SIGNALS
  * (accountFallback.ts) and would flip the connection into a terminal
  * credits_exhausted state — never use them as markers here.
+ *
+ * Accepted trade-off: matching only on response body text means a
+ * legitimate 400 whose body ECHOES user-supplied content containing a
+ * marker (e.g. a prompt that itself contains "额度不足") would be restated to
+ * 429 and lose the combo's 400 stop-guard. This is treated as an acceptable
+ * risk because these markers are rare outside a genuine upstream error;
+ * keeping markers short, provider-specific, and non-generic (as above)
+ * minimizes false-positive restatement.
  */
 
 export type UpstreamStatusRestatementRule = {
diff --git a/tests/unit/agentrouter-error-rules.test.ts b/tests/unit/agentrouter-error-rules.test.ts
index d9cecd78fd..2315a3076c 100644
--- a/tests/unit/agentrouter-error-rules.test.ts
+++ b/tests/unit/agentrouter-error-rules.test.ts
@@ -2,14 +2,27 @@ import test from "node:test";
 import assert from "node:assert/strict";
 
 /**
- * agentrouter.org quota model:
- *  - "额度不足" (quota insufficient) is ACCOUNT-wide and temporary → lock the
- *    connection (scope "connection") so combo routing moves to another
- *    account/provider instead of hammering the same key.
- *  - "无权访问模型" (no access to this model) is permanent PER MODEL → lock only
- *    the model (scope "model"); the connection keeps serving other models.
+ * agentrouter.org quota model, as declared by the `providerErrorRules.ts`
+ * classification layer:
+ *  - "额度不足" (quota insufficient) is ACCOUNT-wide and temporary → the rule
+ *    declares scope "connection".
+ *  - "无权访问模型" (no access to this model) is permanent PER MODEL → the rule
+ *    declares scope "model".
  * Status matching accepts both the raw upstream 403 AND the restated 429
  * (upstreamStatusRestatement.ts rewrites 403→429 before classification).
+ *
+ * IMPORTANT — `scope` above is what the rule DECLARES, not what production
+ * enforces: `ProviderErrorRuleMatch.scope` is not consumed by
+ * checkFallbackError/combo.ts today (only `reason`/`cooldownMs` are). For
+ * agentrouter (passthroughModels: true → hasPerModelQuota() true), the
+ * quota_exhausted match actually resolves to a PER-MODEL lockout in
+ * production, not a connection-wide lock — other models on the same account
+ * keep being tried by combo routing until they lock out individually. And
+ * the "无权访问模型" rule never reaches production traffic at all today: it
+ * only matches raw `status === 403`, but checkFallbackError's apikey
+ * FORBIDDEN branch returns early for a plain 403 before any provider rule is
+ * consulted (see A7). See `docs/architecture/RESILIENCE_GUIDE.md` §7 for the
+ * full writeup and the tracked follow-up to honor `scope`.
  */
 
 const { providerRuleRegistry, getProviderErrorRuleMatch } = await import(
@@ -40,7 +53,7 @@ test("A3: quota body also matches the raw (pre-restatement) 403", () => {
   assert.equal(match.reason, "quota_exhausted");
 });
 
-test("A4: 无权访问模型 → auth_error scope model (model lockout, not connection)", () => {
+test("A4: 无权访问模型 → auth_error scope model, at the RULE layer only (getProviderErrorRuleMatch directly) — this rule never receives production traffic (see A7): checkFallbackError's apikey FORBIDDEN branch returns early for a plain 403 before reaching this rule", () => {
   const match = getProviderErrorRuleMatch("agentrouter", 403, {}, {
     error: { message: "无权访问模型 claude-sonnet-4" },
   });
@@ -49,7 +62,7 @@ test("A4: 无权访问模型 → auth_error scope model (model lockout, not conn
   assert.equal(match.scope, "model");
 });
 
-test("A5: classifyError integration — quota text wins over the 403→AUTH_ERROR status fallback", () => {
+test("A5: classifyError layer guard — quota text wins over the 403→AUTH_ERROR status fallback (classifyError itself has no production caller today; the production guard is A6/checkFallbackError)", () => {
   const reason = classifyError(403, "用户额度不足", {
     provider: "agentrouter",
     headers: {},