diff --git a/src/agent/tool-aliases.test.ts b/src/agent/tool-aliases.test.ts
index 4b4a40ae5..de0c40cca 100644
--- a/src/agent/tool-aliases.test.ts
+++ b/src/agent/tool-aliases.test.ts
@@ -1,9 +1,14 @@
 import { describe, expect, test } from "bun:test";
-import type { ToolDefinition } from "@intx/types/runtime";
+import type { ToolCall, ToolDefinition } from "@intx/types/runtime";
 import { createDynamicToolRunner } from "../tui/dynamic-tool-runner.js";
 import { advertisedTools } from "./tool-search.js";
 import { canonicalToolName } from "./canonical-tool-name.js";
-import { advertisedToolName, WIRE_TO_ENGINE } from "./tool-aliases.js";
+import {
+  advertisedToolName,
+  authzParityDefinitions,
+  withAuthzParityDefinitions,
+  WIRE_TO_ENGINE,
+} from "./tool-aliases.js";
 import { evaluateApprovals } from "../permission/authz-grants.js";
 
 const noWorkspace = { resolvedCwd: "/repo", roots: ["/repo"] };
@@ -240,3 +245,152 @@ describe("hidden alias dispatch", () => {
     expect(new Set(names).size).toBe(names.length);
   });
 });
+
+describe("authz parity definitions", () => {
+  test("run_shell gains bash and shell copies that rename name only", () => {
+    const native = posixDef("run_shell");
+    const defs = authzParityDefinitions([native]);
+    expect(defs.map((d) => d.name)).toEqual(["run_shell", "bash", "shell"]);
+    const byName = new Map(defs.map((d) => [d.name, d]));
+    expect(byName.get("run_shell")).toBe(native);
+    expect(byName.get("bash")).toEqual({ ...native, name: "bash" });
+    expect(byName.get("shell")).toEqual({ ...native, name: "shell" });
+  });
+
+  test("read_file gains a read copy; MCP defs pass through untouched", () => {
+    const mcp = posixDef("mcp__linear__save_issue");
+    const defs = authzParityDefinitions([posixDef("read_file"), mcp]);
+    expect(defs.map((d) => d.name)).toEqual([
+      "read_file",
+      "mcp__linear__save_issue",
+      "read",
+    ]);
+    expect(defs.find((d) => d.name === "mcp__linear__save_issue")).toBe(mcp);
+  });
+
+  test("manage_tasks never gains an update_plan snapshot copy", () => {
+    const defs = authzParityDefinitions([
+      posixDef("manage_tasks"),
+      posixDef("run_shell"),
+    ]);
+    const names = defs.map((d) => d.name);
+    expect(names).toContain("manage_tasks");
+    expect(names).not.toContain("update_plan");
+    expect(names).toContain("bash");
+    expect(names).toContain("shell");
+  });
+
+  test("already-aliased and duplicate defs dedup by name", () => {
+    const defs = authzParityDefinitions([
+      posixDef("run_shell"),
+      posixDef("bash"),
+      posixDef("run_shell"),
+    ]);
+    expect(defs.map((d) => d.name)).toEqual(["run_shell", "bash", "shell"]);
+  });
+
+  test("empty registry stays empty", () => {
+    expect(authzParityDefinitions([])).toEqual([]);
+  });
+
+  test("applied to its own output is a no-op (name set stable)", () => {
+    const once = authzParityDefinitions([
+      posixDef("run_shell"),
+      posixDef("read_file"),
+      posixDef("manage_tasks"),
+      posixDef("mcp__acme__do"),
+    ]);
+    const twice = authzParityDefinitions(once);
+    expect(twice.map((d) => d.name)).toEqual(once.map((d) => d.name));
+    expect(twice).toEqual(once);
+  });
+});
+
+describe("withAuthzParityDefinitions", () => {
+  test("definitions getter returns parity over the live set; run delegates", async () => {
+    let live: ToolDefinition[] = [posixDef("run_shell")];
+    let ran: ToolCall | undefined;
+    const bundle = {
+      definitions: live,
+      currentDefinitions: () => live,
+      run: async (call: ToolCall, _signal: AbortSignal) => {
+        ran = call;
+        return { callId: call.id, content: "ok", isError: false };
+      },
+      addTools: () => undefined,
+      setCallGate: () => undefined,
+    };
+    const wrapped = withAuthzParityDefinitions(bundle);
+    expect(wrapped.definitions.map((d) => d.name)).toEqual([
+      "run_shell",
+      "bash",
+      "shell",
+    ]);
+    live = [...live, posixDef("mcp__acme__do")];
+    expect(wrapped.definitions.map((d) => d.name)).toEqual([
+      "run_shell",
+      "mcp__acme__do",
+      "bash",
+      "shell",
+    ]);
+    const call = {
+      id: "1",
+      name: "bash",
+      arguments: { command: "echo hi" },
+    };
+    await wrapped.run(call, new AbortController().signal);
+    expect(ran).toBe(call);
+  });
+
+  test("falls back to definitions when currentDefinitions is absent", () => {
+    const bundle = {
+      definitions: [posixDef("read_file")] as readonly ToolDefinition[],
+      run: async () => ({ callId: "1", content: "", isError: false }),
+    };
+    expect(
+      withAuthzParityDefinitions(bundle).definitions.map((d) => d.name),
+    ).toEqual(["read_file", "read"]);
+  });
+
+  test("addTools through the wrapper is reflected in definitions plus parity copies", () => {
+    let live: ToolDefinition[] = [posixDef("run_shell")];
+    const bundle = {
+      definitions: live,
+      currentDefinitions: () => live,
+      addTools: (tools: ToolDefinition[]) => {
+        live = [...live, ...tools];
+      },
+      run: async () => ({ callId: "1", content: "", isError: false }),
+    };
+    const wrapped = withAuthzParityDefinitions(bundle);
+    expect(wrapped.addTools).toBe(bundle.addTools);
+    wrapped.addTools([posixDef("read_file")]);
+    expect(wrapped.definitions.map((d) => d.name)).toEqual([
+      "run_shell",
+      "read_file",
+      "bash",
+      "shell",
+      "read",
+    ]);
+  });
+
+  test("removeTools through the wrapper is reflected in definitions", () => {
+    let live: ToolDefinition[] = [posixDef("run_shell"), posixDef("read_file")];
+    const bundle = {
+      definitions: live,
+      currentDefinitions: () => live,
+      removeTools: (names: string[]) => {
+        live = live.filter((d) => !names.includes(d.name));
+      },
+      run: async () => ({ callId: "1", content: "", isError: false }),
+    };
+    const wrapped = withAuthzParityDefinitions(bundle);
+    expect(wrapped.removeTools).toBe(bundle.removeTools);
+    wrapped.removeTools(["read_file"]);
+    expect(wrapped.definitions.map((d) => d.name)).toEqual([
+      "run_shell",
+      "bash",
+      "shell",
+    ]);
+  });
+});
diff --git a/src/agent/tool-aliases.ts b/src/agent/tool-aliases.ts
index 20f4e7f27..5bed3650e 100644
--- a/src/agent/tool-aliases.ts
+++ b/src/agent/tool-aliases.ts
@@ -11,6 +11,7 @@
 
 import { type } from "arktype";
 import type { ToolCall, ToolDefinition } from "@intx/types/runtime";
+import { canonicalToolName } from "./canonical-tool-name.js";
 
 /** Advertised posix names → registry engine ids. 1:1, never dual-publish. */
 export const WIRE_TO_ENGINE = {
@@ -77,6 +78,67 @@ export function projectToolDefinitions(
   return defs.map(projectToolDefinition);
 }
 
+/**
+ * Authz parity definitions: every def unchanged, plus one `{...def, name:
+ * alias}` copy for each alias in ALIAS_TO_ENGINE whose engine equals the
+ * def's canonical name. The reactor authz snapshot is keyed by parked wire
+ * name, so without these copies an ask-tier `bash`/`shell` call throws a
+ * wiring-defect error instead of suspending.
+ *
+ * `update_plan` is never snapshotted: its grant is create-only narrow, so no
+ * `update_plan`-named copy is emitted. Non-aliased defs (MCP, leaf-only)
+ * pass through unchanged. Output is deduplicated by name.
+ */
+export function authzParityDefinitions(
+  defs: readonly ToolDefinition[],
+): ToolDefinition[] {
+  const seen = new Set<string>();
+  const out: ToolDefinition[] = [];
+  const push = (def: ToolDefinition): void => {
+    if (seen.has(def.name)) return;
+    seen.add(def.name);
+    out.push(def);
+  };
+  for (const def of defs) push(def);
+  for (const def of defs) {
+    const engine = canonicalToolName(def.name);
+    for (const [alias, aliasEngine] of Object.entries(ALIAS_TO_ENGINE)) {
+      if (aliasEngine !== engine) continue;
+      if (alias === "update_plan") continue;
+      push({ ...def, name: alias });
+    }
+  }
+  return out;
+}
+
+/**
+ * Thin wrapper over a tool bundle (e.g. DynamicToolRunner): identical except
+ * the `definitions` getter returns `authzParityDefinitions` over the live
+ * set. Run/dispatch and mutation entry points delegate verbatim — only the
+ * authz-facing definition set gains parity copies. The advertised wire set
+ * is untouched (advertise still projects through computeAdvertised).
+ */
+export function withAuthzParityDefinitions<
+  T extends { readonly definitions: readonly ToolDefinition[] },
+>(bundle: T): T {
+  const wrapped = { ...bundle };
+  const liveSource = bundle as Partial<{
+    currentDefinitions: () => readonly ToolDefinition[];
+  }>;
+  Object.defineProperty(wrapped, "definitions", {
+    get() {
+      const live =
+        typeof liveSource.currentDefinitions === "function"
+          ? liveSource.currentDefinitions()
+          : bundle.definitions;
+      return authzParityDefinitions(live);
+    },
+    enumerable: true,
+    configurable: true,
+  });
+  return wrapped;
+}
+
 const SHELL_WRAPPERS = new Set(["bash", "sh", "zsh"]);
 
 function shellQuote(arg: string): string {
diff --git a/src/permission/reactor-authorize.test.ts b/src/permission/reactor-authorize.test.ts
index 99fc830bf..d1b7a1343 100644
--- a/src/permission/reactor-authorize.test.ts
+++ b/src/permission/reactor-authorize.test.ts
@@ -2,12 +2,19 @@ import { expect, test } from "bun:test";
 import { mkdtempSync, realpathSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
+import { createAuthzExtension } from "@intx/inference";
+import type {
+  ToolDefinition,
+  ReactorState,
+  TokenUsage,
+} from "@intx/types/runtime";
 import { createPermissionGate } from "./gate.js";
 import {
   createReactorAuthorize,
   createWorkerAuthorize,
   workerPermissionGate,
 } from "./reactor-authorize.js";
+import { authzParityDefinitions } from "../agent/tool-aliases.js";
 import {
   runWithSubAgentIdentity,
   getSubAgentIdentity,
@@ -335,3 +342,125 @@ test("concurrent authorization preserves each worker cwd across awaited policy e
   expect(seen.sort()).toEqual(["/worker-a", "/worker-b"]);
   expect(getSubAgentIdentity()).toBeUndefined();
 });
+
+const shellDef = (name: string): ToolDefinition => ({
+  name,
+  description: `${name} tool`,
+  inputSchema: { type: "object", properties: {} },
+});
+
+const emptyUsage = (): TokenUsage => ({
+  input: 0,
+  output: 0,
+  cacheRead: 0,
+  cacheWrite: 0,
+  thinking: 0,
+});
+
+const askState = (): ReactorState => ({
+  sessionId: "parity-ask",
+  turns: [],
+  activeForks: [],
+  pendingOperations: [],
+  activeGates: [],
+  tokenUsage: emptyUsage(),
+  lastCycleUsage: null,
+  lastCycleSource: null,
+});
+
+const askSignal = new AbortController().signal;
+
+test("ask-tier shell aliases suspend with a wire-named snapshot", async () => {
+  const policy = gate({ interactive: true });
+  const ext = createAuthzExtension({
+    toolDefinitions: authzParityDefinitions([
+      shellDef("run_shell"),
+      shellDef("read_file"),
+    ]),
+    authorize: createReactorAuthorize(policy),
+  });
+  for (const name of ["bash", "run_shell", "shell"]) {
+    const toolCall = namedCall(name, { command: "sleep 30" });
+    const outcome = await ext.beforeTool(toolCall, askState(), askSignal);
+    if (outcome.type !== "suspend") throw new Error(`expected ${name} to park`);
+    expect(outcome.pendingOp.approvalSnapshot?.name).toBe(name);
+    expect(outcome.pendingOp.approvalSnapshot?.arguments).toEqual({
+      command: "sleep 30",
+    });
+    expect(outcome.pendingOp.suspendedCall).toEqual(toolCall);
+  }
+});
+
+test("seeded run_shell grant allows bash, run_shell, and shell", async () => {
+  const policy = gate({ interactive: true });
+  policy.setSeededApprovals([{ tool: "run_shell", pattern: "echo *" }]);
+  const ext = createAuthzExtension({
+    toolDefinitions: authzParityDefinitions([shellDef("run_shell")]),
+    authorize: createReactorAuthorize(policy),
+  });
+  for (const name of ["bash", "run_shell", "shell"]) {
+    const outcome = await ext.beforeTool(
+      namedCall(name, { command: "echo hi" }),
+      askState(),
+      askSignal,
+    );
+    expect(outcome.type).toBe("allow");
+  }
+});
+
+test("ask on a tool missing from the resolved set still throws", async () => {
+  const policy = gate({ interactive: true });
+  const ext = createAuthzExtension({
+    toolDefinitions: authzParityDefinitions([shellDef("read_file")]),
+    authorize: createReactorAuthorize(policy),
+  });
+  await expect(
+    ext.beforeTool(
+      namedCall("bash", { command: "sleep 30" }),
+      askState(),
+      askSignal,
+    ),
+  ).rejects.toThrow(/wiring defect/);
+});
+
+test("approved ask resumes the exact parked call once via one-shot bypass", async () => {
+  const policy = gate({ interactive: true });
+  const reactorAuthorize = createReactorAuthorize(policy);
+  const seen: ToolCall[] = [];
+  const ext = createAuthzExtension<ToolCall>({
+    toolDefinitions: authzParityDefinitions([shellDef("run_shell")]),
+    authorize: (resource, action, call) => {
+      seen.push(call);
+      return reactorAuthorize(resource, action, call);
+    },
+  });
+  for (const name of ["bash", "run_shell"]) {
+    const toolCall = namedCall(name, { command: "sleep 30" });
+    const parked = await ext.beforeTool(toolCall, askState(), askSignal);
+    if (parked.type !== "suspend") throw new Error(`expected ${name} to park`);
+    expect(parked.pendingOp.approvalSnapshot?.name).toBe(name);
+    ext.grantOneShot?.(toolCall.id);
+    const resumed = await ext.beforeTool(toolCall, askState(), askSignal);
+    expect(resumed.type).toBe("allow");
+    expect(seen[seen.length - 1]).toEqual(parked.pendingOp.suspendedCall);
+    const reparked = await ext.beforeTool(toolCall, askState(), askSignal);
+    expect(reparked.type).toBe("suspend");
+  }
+});
+
+test("denied shell call blocks with a policy error", async () => {
+  const policy = gate({ interactive: false });
+  const ext = createAuthzExtension({
+    toolDefinitions: authzParityDefinitions([shellDef("run_shell")]),
+    authorize: createReactorAuthorize(policy),
+  });
+  for (const name of ["bash", "run_shell"]) {
+    const outcome = await ext.beforeTool(
+      namedCall(name, { command: "sleep 30" }),
+      askState(),
+      askSignal,
+    );
+    if (outcome.type !== "block") throw new Error(`expected ${name} to block`);
+    expect(outcome.reason).toMatch(/Denied by policy/);
+  }
+});
diff --git a/src/session/assemble-runtime.test.ts b/src/session/assemble-runtime.test.ts
index 228b678ea..101bc22bb 100644
--- a/src/session/assemble-runtime.test.ts
+++ b/src/session/assemble-runtime.test.ts
@@ -12,6 +12,7 @@ import type {
 
 import { withMockedModuleDuring } from "../../testkit/mock-module.js";
 import type { ChatDirector } from "../agent/director.js";
+import { authzParityDefinitions } from "../agent/tool-aliases.js";
 import {
   createAdvertisedToolset,
   loadSessionLocalSettings,
@@ -101,6 +102,33 @@ describe("createAdvertisedToolset", () => {
     ).toEqual(["read"]);
   });
 
+  test("parity defs cover native and wire names while the wire set stays byte-identical", () => {
+    const native = [
+      def("run_shell"),
+      def("read_file"),
+      def("mcp__linear__save_issue"),
+    ];
+    const parity = authzParityDefinitions(native);
+    const parityNames = new Set(parity.map((d) => d.name));
+    for (const name of [
+      "run_shell",
+      "read_file",
+      "mcp__linear__save_issue",
+      "bash",
+      "shell",
+      "read",
+    ]) {
+      expect(parityNames.has(name)).toBe(true);
+    }
+    expect(parityNames.has("update_plan")).toBe(false);
+    const { computeAdvertised } = createAdvertisedToolset(wiring());
+    expect(JSON.stringify(computeAdvertised(parity))).toBe(
+      JSON.stringify(computeAdvertised(native)),
+    );
+    const wireNames = computeAdvertised(parity).map((d) => d.name);
+    expect(new Set(wireNames).size).toBe(wireNames.length);
+  });
+
   test("isAdvertised tracks prefix, pinned, and activated names", () => {
     const { activated, isAdvertised } = createAdvertisedToolset(
       wiring({ pinnedTools: ["mcp__linear__save_issue"] }),
diff --git a/src/session/assemble-runtime.ts b/src/session/assemble-runtime.ts
index 1e1cf773e..893e97145 100644
--- a/src/session/assemble-runtime.ts
+++ b/src/session/assemble-runtime.ts
@@ -49,7 +49,10 @@ import {
   type ActivatedToolTracker,
   type ToolAvailability,
 } from "../agent/tool-search.js";
-import { nameMatchesAdvertisedListing } from "../agent/tool-aliases.js";
+import {
+  nameMatchesAdvertisedListing,
+  withAuthzParityDefinitions,
+} from "../agent/tool-aliases.js";
 import { canonicalToolName } from "../agent/canonical-tool-name.js";
 import { normalizeToolDefinitionsForProvider } from "../agent/tool-schema-normalize.js";
 import { resolveModelFamilyPolicy } from "../agent/model-family-policy.js";
@@ -612,7 +615,7 @@ export function assembleChatAgent(wiring: ChatAgentWiring): AssembledChatAgent {
   const toolsFactory = defineTool({
     id: wiring.toolsId,
     definitions: [],
-    factory: () => wiring.getDynamicRunner(),
+    factory: () => withAuthzParityDefinitions(wiring.getDynamicRunner()),
   });
 
   const provider = wiring.getProvider();
diff --git a/src/subagent/run.ts b/src/subagent/run.ts
index e35b395b5..9e32a82b9 100644
--- a/src/subagent/run.ts
+++ b/src/subagent/run.ts
@@ -70,6 +70,7 @@ import { canonicalToolName } from "../agent/canonical-tool-name.js";
 import {
   advertisedToolName,
   projectToolDefinitions,
+  withAuthzParityDefinitions,
 } from "../agent/tool-aliases.js";
 
 import {
@@ -1126,11 +1127,11 @@ async function runSubAgentInner(
           tools,
           toolWatchdogFromSettings(params.settings),
         );
-        return {
+        return withAuthzParityDefinitions({
           ...runner,
           run: (call, signal) =>
             withWorkerIdentity(() => runner.run(call, signal)),
-        };
+        });
       },
     });