diff --git a/packages/core/src/hooks/types.test.ts b/packages/core/src/hooks/types.test.ts
index 8853b5a103..d8fbb79488 100644
--- a/packages/core/src/hooks/types.test.ts
+++ b/packages/core/src/hooks/types.test.ts
@@ -8,7 +8,6 @@ import { describe, it, expect, vi } from 'vitest';
 import {
   createHookOutput,
   DefaultHookOutput,
-  BeforeToolHookOutput,
   BeforeModelHookOutput,
   BeforeToolSelectionHookOutput,
   AfterModelHookOutput,
@@ -208,33 +207,6 @@ describe('Hook Output Classes', () => {
     });
   });
 
-  describe('BeforeToolHookOutput', () => {
-    it('isBlockingDecision should use permissionDecision from hookSpecificOutput', () => {
-      const output1 = new BeforeToolHookOutput({
-        hookSpecificOutput: { permissionDecision: 'block' },
-      });
-      expect(output1.isBlockingDecision()).toBe(true);
-
-      const output2 = new BeforeToolHookOutput({
-        hookSpecificOutput: { permissionDecision: 'approve' },
-      });
-      expect(output2.isBlockingDecision()).toBe(false);
-    });
-
-    it('getEffectiveReason should use permissionDecisionReason from hookSpecificOutput', () => {
-      const output1 = new BeforeToolHookOutput({
-        hookSpecificOutput: { permissionDecisionReason: 'compat reason' },
-      });
-      expect(output1.getEffectiveReason()).toBe('compat reason');
-
-      const output2 = new BeforeToolHookOutput({
-        reason: 'default reason',
-        hookSpecificOutput: { other: 'value' },
-      });
-      expect(output2.getEffectiveReason()).toBe('default reason');
-    });
-  });
-
   describe('BeforeModelHookOutput', () => {
     it('getSyntheticResponse should return synthetic response if llm_response is present', () => {
       const mockResponse: LLMResponse = { candidates: [] };
diff --git a/packages/core/src/hooks/types.ts b/packages/core/src/hooks/types.ts
index 8e9f8cd047..610019ff8f 100644
--- a/packages/core/src/hooks/types.ts
+++ b/packages/core/src/hooks/types.ts
@@ -225,45 +225,9 @@ export class DefaultHookOutput implements HookOutput {
 }
 
 /**
- * Specific hook output class for BeforeTool events with compatibility support
+ * Specific hook output class for BeforeTool events.
  */
-export class BeforeToolHookOutput extends DefaultHookOutput {
-  /**
-   * Get the effective blocking reason, considering compatibility fields
-   */
-  override getEffectiveReason(): string {
-    // Check for compatibility fields first
-    if (this.hookSpecificOutput) {
-      if ('permissionDecisionReason' in this.hookSpecificOutput) {
-        const compatReason =
-          this.hookSpecificOutput['permissionDecisionReason'];
-        if (typeof compatReason === 'string') {
-          return compatReason;
-        }
-      }
-    }
-
-    return super.getEffectiveReason();
-  }
-
-  /**
-   * Check if this output represents a blocking decision, considering compatibility fields
-   */
-  override isBlockingDecision(): boolean {
-    // Check compatibility field first
-    if (
-      this.hookSpecificOutput &&
-      'permissionDecision' in this.hookSpecificOutput
-    ) {
-      const compatDecision = this.hookSpecificOutput['permissionDecision'];
-      if (compatDecision === 'block' || compatDecision === 'deny') {
-        return true;
-      }
-    }
-
-    return super.isBlockingDecision();
-  }
-}
+export class BeforeToolHookOutput extends DefaultHookOutput {}
 
 /**
  * Specific hook output class for BeforeModel events
@@ -395,8 +359,6 @@ export interface BeforeToolInput extends HookInput {
 export interface BeforeToolOutput extends HookOutput {
   hookSpecificOutput?: {
     hookEventName: 'BeforeTool';
-    permissionDecision?: HookDecision;
-    permissionDecisionReason?: string;
   };
 }