diff --git a/sdk/src/gsd-tools-error.ts b/sdk/src/gsd-tools-error.ts
index 68a5a1bc6..bc5d79880 100644
--- a/sdk/src/gsd-tools-error.ts
+++ b/sdk/src/gsd-tools-error.ts
@@ -3,6 +3,14 @@ export interface GSDToolsErrorClassification {
   timeoutMs?: number;
 }
 
+export function timeoutClassification(timeoutMs?: number): GSDToolsErrorClassification {
+  return timeoutMs === undefined ? { kind: 'timeout' } : { kind: 'timeout', timeoutMs };
+}
+
+export function failureClassification(): GSDToolsErrorClassification {
+  return { kind: 'failure' };
+}
+
 export class GSDToolsError extends Error {
   constructor(
     message: string,
diff --git a/sdk/src/query-failure-classification.test.ts b/sdk/src/query-failure-classification.test.ts
index 4232304c7..5f3774c74 100644
--- a/sdk/src/query-failure-classification.test.ts
+++ b/sdk/src/query-failure-classification.test.ts
@@ -1,7 +1,6 @@
 import { describe, expect, it } from 'vitest';
 import {
   errorMessage,
-  isTimeoutLikeError,
   isTimeoutMessage,
   parseTimeoutMs,
   timeoutMessage,
@@ -16,13 +15,6 @@ describe('query failure classification', () => {
     expect(parseTimeoutMs(msg)).toBe(30000);
   });
 
-  it('classifies timeout-like errors', () => {
-    expect(isTimeoutLikeError(new Error('gsd-tools timed out after 1000ms: x'))).toBe(true);
-    const abort = new Error('aborted');
-    abort.name = 'AbortError';
-    expect(isTimeoutLikeError(abort)).toBe(true);
-  });
-
   it('normalizes unknown error values', () => {
     expect(errorMessage('boom')).toBe('boom');
     expect(errorMessage(new Error('x'))).toBe('x');
diff --git a/sdk/src/query-failure-classification.ts b/sdk/src/query-failure-classification.ts
index 5fdda719e..e5a4a8aad 100644
--- a/sdk/src/query-failure-classification.ts
+++ b/sdk/src/query-failure-classification.ts
@@ -21,12 +21,6 @@ export function isTimeoutMessage(message: string): boolean {
   return /timed out after/i.test(message);
 }
 
-export function isTimeoutLikeError(error: unknown): boolean {
-  if (!(error instanceof Error)) return false;
-  if (error.name === 'TimeoutError' || error.name === 'AbortError') return true;
-  return isTimeoutMessage(error.message);
-}
-
 export function timeoutMessage(command: string, args: string[], timeoutMs: number): string {
   return `gsd-tools timed out after ${timeoutMs}ms: ${command} ${args.join(' ')}`;
 }
diff --git a/sdk/src/query-gsd-tools-runtime.ts b/sdk/src/query-gsd-tools-runtime.ts
index 6ff59c513..3a9f72d92 100644
--- a/sdk/src/query-gsd-tools-runtime.ts
+++ b/sdk/src/query-gsd-tools-runtime.ts
@@ -7,7 +7,7 @@ import { QuerySubprocessAdapter } from './query-subprocess-adapter.js';
 import { QueryNativeDirectAdapter } from './query-native-direct-adapter.js';
 import { QueryNativeHotpathAdapter } from './query-native-hotpath-adapter.js';
 import { formatQueryRawOutput } from './query-raw-output-projection.js';
-import { GSDToolsError } from './gsd-tools-error.js';
+import { failureClassification, GSDToolsError, timeoutClassification } from './gsd-tools-error.js';
 
 export interface GSDToolsRuntime {
   registry: ReturnType<typeof createRegistry>;
@@ -35,7 +35,7 @@ export function createGSDToolsRuntime(opts: {
     workstream: opts.workstream,
     createToolsError: (message, command, args, exitCode, stderr, classification) =>
       new GSDToolsError(message, command, args, exitCode, stderr, {
-        classification: classification ?? { kind: 'failure' },
+        classification: classification ?? failureClassification(),
       }),
   });
 
@@ -43,7 +43,7 @@ export function createGSDToolsRuntime(opts: {
     timeoutMs: opts.timeoutMs,
     dispatch: (registryCommand, registryArgs) => registry.dispatch(registryCommand, registryArgs, opts.projectDir),
     createTimeoutError: (message, command, args) =>
-      new GSDToolsError(message, command, args, null, '', { classification: { kind: 'timeout', timeoutMs: opts.timeoutMs } }),
+      new GSDToolsError(message, command, args, null, '', { classification: timeoutClassification(opts.timeoutMs) }),
   });
 
   const transport = new GSDTransport(registry, {
diff --git a/sdk/src/query-tools-error-mapper.ts b/sdk/src/query-tools-error-mapper.ts
index 357af2fe4..ee58ec0a8 100644
--- a/sdk/src/query-tools-error-mapper.ts
+++ b/sdk/src/query-tools-error-mapper.ts
@@ -1,5 +1,5 @@
 import { GSDError, exitCodeFor } from './errors.js';
-import { GSDToolsError } from './gsd-tools-error.js';
+import { failureClassification, GSDToolsError, timeoutClassification } from './gsd-tools-error.js';
 import { errorMessage, toFailureSignal } from './query-failure-classification.js';
 
 /**
@@ -20,8 +20,8 @@ export function toGSDToolsError(command: string, args: string[], err: unknown):
   const msg = errorMessage(err);
   const signal = toFailureSignal(err);
   const classification = signal.kind === 'timeout'
-    ? { kind: 'timeout' as const, timeoutMs: signal.timeoutMs }
-    : { kind: 'failure' as const };
+    ? timeoutClassification(signal.timeoutMs)
+    : failureClassification();
 
   return new GSDToolsError(
     msg,