4 files changed, 14 insertions, 3 deletions
diff --git a/packages/core/src/telemetry/loggers.test.circular.ts b/packages/core/src/telemetry/loggers.test.circular.ts
index 62a61bfd..80444a0d 100644
--- a/packages/core/src/telemetry/loggers.test.circular.ts
+++ b/packages/core/src/telemetry/loggers.test.circular.ts
@@ -53,6 +53,7 @@ describe('Circular Reference Handling', () => {
       responseParts: [{ text: 'test result' }],
       resultDisplay: undefined,
       error: undefined, // undefined means success
+      errorType: undefined,
     };
 
     const mockCompletedToolCall: CompletedToolCall = {
@@ -100,6 +101,7 @@ describe('Circular Reference Handling', () => {
       responseParts: [{ text: 'test result' }],
       resultDisplay: undefined,
       error: undefined, // undefined means success
+      errorType: undefined,
     };
 
     const mockCompletedToolCall: CompletedToolCall = {
diff --git a/packages/core/src/telemetry/loggers.test.ts b/packages/core/src/telemetry/loggers.test.ts
index 7a24bcca..3d8116cc 100644
--- a/packages/core/src/telemetry/loggers.test.ts
+++ b/packages/core/src/telemetry/loggers.test.ts
@@ -12,6 +12,7 @@ import {
   ErroredToolCall,
   GeminiClient,
   ToolConfirmationOutcome,
+  ToolErrorType,
   ToolRegistry,
 } from '../index.js';
 import { logs } from '@opentelemetry/api-logs';
@@ -448,6 +449,7 @@ describe('loggers', () => {
           responseParts: 'test-response',
           resultDisplay: undefined,
           error: undefined,
+          errorType: undefined,
         },
         tool: new EditTool(mockConfig),
         durationMs: 100,
@@ -511,6 +513,7 @@ describe('loggers', () => {
           responseParts: 'test-response',
           resultDisplay: undefined,
           error: undefined,
+          errorType: undefined,
         },
         durationMs: 100,
         outcome: ToolConfirmationOutcome.Cancel,
@@ -574,6 +577,7 @@ describe('loggers', () => {
           responseParts: 'test-response',
           resultDisplay: undefined,
           error: undefined,
+          errorType: undefined,
         },
         outcome: ToolConfirmationOutcome.ModifyWithEditor,
         tool: new EditTool(mockConfig),
@@ -638,6 +642,7 @@ describe('loggers', () => {
           responseParts: 'test-response',
           resultDisplay: undefined,
           error: undefined,
+          errorType: undefined,
         },
         tool: new EditTool(mockConfig),
         durationMs: 100,
@@ -703,6 +708,7 @@ describe('loggers', () => {
             name: 'test-error-type',
             message: 'test-error',
           },
+          errorType: ToolErrorType.UNKNOWN,
         },
         durationMs: 100,
       };
@@ -729,8 +735,8 @@ describe('loggers', () => {
           success: false,
           error: 'test-error',
           'error.message': 'test-error',
-          error_type: 'test-error-type',
-          'error.type': 'test-error-type',
+          error_type: ToolErrorType.UNKNOWN,
+          'error.type': ToolErrorType.UNKNOWN,
           prompt_id: 'prompt-id-5',
         },
       });
diff --git a/packages/core/src/telemetry/types.ts b/packages/core/src/telemetry/types.ts
index 1633dbc4..9d1fd77a 100644
--- a/packages/core/src/telemetry/types.ts
+++ b/packages/core/src/telemetry/types.ts
@@ -137,7 +137,7 @@ export class ToolCallEvent {
       ? getDecisionFromOutcome(call.outcome)
       : undefined;
     this.error = call.response.error?.message;
-    this.error_type = call.response.error?.name;
+    this.error_type = call.response.errorType;
     this.prompt_id = call.request.prompt_id;
   }
 }
diff --git a/packages/core/src/telemetry/uiTelemetry.test.ts b/packages/core/src/telemetry/uiTelemetry.test.ts
index 38ba7a91..bce54ad8 100644
--- a/packages/core/src/telemetry/uiTelemetry.test.ts
+++ b/packages/core/src/telemetry/uiTelemetry.test.ts
@@ -22,6 +22,7 @@ import {
   ErroredToolCall,
   SuccessfulToolCall,
 } from '../core/coreToolScheduler.js';
+import { ToolErrorType } from '../tools/tool-error.js';
 import { Tool, ToolConfirmationOutcome } from '../tools/tools.js';
 
 const createFakeCompletedToolCall = (
@@ -54,6 +55,7 @@ const createFakeCompletedToolCall = (
           },
         },
         error: undefined,
+        errorType: undefined,
         resultDisplay: 'Success!',
       },
       durationMs: duration,
@@ -73,6 +75,7 @@ const createFakeCompletedToolCall = (
           },
         },
         error: error || new Error('Tool failed'),
+        errorType: ToolErrorType.UNKNOWN,
         resultDisplay: 'Failure!',
       },
       durationMs: duration,