diff --git a/packages/core/src/tools/edit.ts b/packages/core/src/tools/edit.ts
index 06f9657745..6b9efdaafa 100644
--- a/packages/core/src/tools/edit.ts
+++ b/packages/core/src/tools/edit.ts
@@ -895,11 +895,33 @@ class EditToolInvocation
           DEFAULT_DIFF_OPTIONS,
         );
 
+        // Determine the full content as originally proposed by the AI to ensure accurate diff stats.
+        let fullAiProposedContent = editData.newContent;
+        if (
+          this.params.modified_by_user &&
+          this.params.ai_proposed_content !== undefined
+        ) {
+          try {
+            const aiReplacement = await calculateReplacement(this.config, {
+              params: {
+                ...this.params,
+                new_string: this.params.ai_proposed_content,
+              },
+              currentContent: editData.currentContent ?? '',
+              abortSignal: signal,
+            });
+            fullAiProposedContent = aiReplacement.newContent;
+          } catch (_e) {
+            // Fallback to newContent if speculative calculation fails
+            fullAiProposedContent = editData.newContent;
+          }
+        }
+
         const diffStat = getDiffStat(
           fileName,
           editData.currentContent ?? '',
+          fullAiProposedContent,
           editData.newContent,
-          this.params.new_string,
         );
         displayResult = {
           fileDiff,
diff --git a/packages/core/src/tools/grep-utils.ts b/packages/core/src/tools/grep-utils.ts
index 2191588301..4d9ab6fb27 100644
--- a/packages/core/src/tools/grep-utils.ts
+++ b/packages/core/src/tools/grep-utils.ts
@@ -7,6 +7,7 @@
 import fsPromises from 'node:fs/promises';
 import { debugLogger } from '../utils/debugLogger.js';
 import { MAX_LINE_LENGTH_TEXT_FILE } from '../utils/constants.js';
+import type { GrepResult } from './tools.js';
 
 /**
  * Result object for a single grep match
@@ -148,12 +149,17 @@ export async function formatGrepResults(
   },
   searchLocationDescription: string,
   totalMaxMatches: number,
-): Promise<{ llmContent: string; returnDisplay: string }> {
+): Promise<{ llmContent: string; returnDisplay: GrepResult }> {
   const { pattern, names_only, include_pattern } = params;
 
   if (allMatches.length === 0) {
     const noMatchMsg = `No matches found for pattern "${pattern}" ${searchLocationDescription}${include_pattern ? ` (filter: "${include_pattern}")` : ''}.`;
-    return { llmContent: noMatchMsg, returnDisplay: `No matches found` };
+    return {
+      llmContent: noMatchMsg,
+      returnDisplay: {
+        summary: `No matches found`,
+      },
+    };
   }
 
   const matchesByFile = groupMatchesByFile(allMatches);
@@ -181,7 +187,9 @@ export async function formatGrepResults(
     llmContent += filePaths.join('\n');
     return {
       llmContent: llmContent.trim(),
-      returnDisplay: `Found ${filePaths.length} files${wasTruncated ? ' (limited)' : ''}`,
+      returnDisplay: {
+        summary: `Found ${filePaths.length} files${wasTruncated ? ' (limited)' : ''}`,
+      },
     };
   }
 
@@ -213,8 +221,15 @@ export async function formatGrepResults(
 
   return {
     llmContent: llmContent.trim(),
-    returnDisplay: `Found ${matchCount} ${matchTerm}${
-      wasTruncated ? ' (limited)' : ''
-    }`,
+    returnDisplay: {
+      summary: `Found ${matchCount} ${matchTerm}${wasTruncated ? ' (limited)' : ''}`,
+      matches: allMatches
+        .filter((m) => !m.isContext)
+        .map((m) => ({
+          filePath: m.filePath,
+          lineNumber: m.lineNumber,
+          line: m.line,
+        })),
+    },
   };
 }
diff --git a/packages/core/src/tools/grep.test.ts b/packages/core/src/tools/grep.test.ts
index 1f0a8ee98f..ea0d03065c 100644
--- a/packages/core/src/tools/grep.test.ts
+++ b/packages/core/src/tools/grep.test.ts
@@ -6,7 +6,7 @@
 
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import { GrepTool, type GrepToolParams } from './grep.js';
-import type { ToolResult } from './tools.js';
+import type { ToolResult, GrepResult } from './tools.js';
 import path from 'node:path';
 import { isSubpath } from '../utils/paths.js';
 import fs from 'node:fs/promises';
@@ -180,7 +180,9 @@ describe('GrepTool', () => {
         `File: ${path.join('sub', 'fileC.txt')}`,
       );
       expect(result.llmContent).toContain('L1: another world in sub dir');
-      expect(result.returnDisplay).toBe('Found 3 matches');
+      expect((result.returnDisplay as GrepResult)?.summary).toBe(
+        'Found 3 matches',
+      );
     }, 30000);
 
     it('should include files that start with ".." in JS fallback', async () => {
@@ -221,7 +223,9 @@ describe('GrepTool', () => {
       );
       expect(result.llmContent).toContain('File: fileC.txt'); // Path relative to 'sub'
       expect(result.llmContent).toContain('L1: another world in sub dir');
-      expect(result.returnDisplay).toBe('Found 1 match');
+      expect((result.returnDisplay as GrepResult)?.summary).toBe(
+        'Found 1 match',
+      );
     }, 30000);
 
     it('should find matches with an include glob', async () => {
@@ -238,7 +242,9 @@ describe('GrepTool', () => {
       expect(result.llmContent).toContain(
         'L2: function baz() { return "hello"; }',
       );
-      expect(result.returnDisplay).toBe('Found 1 match');
+      expect((result.returnDisplay as GrepResult)?.summary).toBe(
+        'Found 1 match',
+      );
     }, 30000);
 
     it('should find matches with an include glob and path', async () => {
@@ -258,7 +264,9 @@ describe('GrepTool', () => {
       );
       expect(result.llmContent).toContain('File: another.js');
       expect(result.llmContent).toContain('L1: const greeting = "hello";');
-      expect(result.returnDisplay).toBe('Found 1 match');
+      expect((result.returnDisplay as GrepResult)?.summary).toBe(
+        'Found 1 match',
+      );
     }, 30000);
 
     it('should return "No matches found" when pattern does not exist', async () => {
@@ -268,7 +276,9 @@ describe('GrepTool', () => {
       expect(result.llmContent).toContain(
         'No matches found for pattern "nonexistentpattern" in the workspace directory.',
       );
-      expect(result.returnDisplay).toBe('No matches found');
+      expect((result.returnDisplay as GrepResult)?.summary).toBe(
+        'No matches found',
+      );
     }, 30000);
 
     it('should handle regex special characters correctly', async () => {
@@ -480,7 +490,9 @@ describe('GrepTool', () => {
       expect(result.llmContent).toContain('L2: second line with world');
       // And sub/fileC.txt should be excluded because limit reached
       expect(result.llmContent).not.toContain('File: sub/fileC.txt');
-      expect(result.returnDisplay).toBe('Found 2 matches (limited)');
+      expect((result.returnDisplay as GrepResult)?.summary).toBe(
+        'Found 2 matches (limited)',
+      );
     });
 
     it('should respect max_matches_per_file in JS fallback', async () => {
diff --git a/packages/core/src/tools/ls.test.ts b/packages/core/src/tools/ls.test.ts
index 63d7693123..12e050d26e 100644
--- a/packages/core/src/tools/ls.test.ts
+++ b/packages/core/src/tools/ls.test.ts
@@ -123,7 +123,10 @@ describe('LSTool', () => {
 
       expect(result.llmContent).toContain('[DIR] subdir');
       expect(result.llmContent).toContain('file1.txt');
-      expect(result.returnDisplay).toBe('Listed 2 item(s).');
+      expect(result.returnDisplay).toEqual({
+        summary: 'Listed 2 item(s).',
+        files: ['[DIR] subdir', 'file1.txt'],
+      });
     });
 
     it('should list files from secondary workspace directory', async () => {
@@ -138,7 +141,10 @@ describe('LSTool', () => {
       const result = await invocation.execute(abortSignal);
 
       expect(result.llmContent).toContain('secondary-file.txt');
-      expect(result.returnDisplay).toBe('Listed 1 item(s).');
+      expect(result.returnDisplay).toEqual({
+        summary: 'Listed 1 item(s).',
+        files: expect.any(Array),
+      });
     });
 
     it('should handle empty directories', async () => {
@@ -148,7 +154,9 @@ describe('LSTool', () => {
       const result = await invocation.execute(abortSignal);
 
       expect(result.llmContent).toBe(`Directory ${emptyDir} is empty.`);
-      expect(result.returnDisplay).toBe('Directory is empty.');
+      expect(result.returnDisplay).toEqual(
+        expect.objectContaining({ summary: 'Directory is empty.' }),
+      );
     });
 
     it('should respect ignore patterns', async () => {
@@ -163,7 +171,10 @@ describe('LSTool', () => {
 
       expect(result.llmContent).toContain('file1.txt');
       expect(result.llmContent).not.toContain('file2.log');
-      expect(result.returnDisplay).toBe('Listed 1 item(s).');
+      expect(result.returnDisplay).toEqual({
+        summary: 'Listed 1 item(s).',
+        files: expect.any(Array),
+      });
     });
 
     it('should respect gitignore patterns', async () => {
@@ -177,7 +188,9 @@ describe('LSTool', () => {
       expect(result.llmContent).toContain('file1.txt');
       expect(result.llmContent).not.toContain('file2.log');
       // .git is always ignored by default.
-      expect(result.returnDisplay).toBe('Listed 2 item(s). (2 ignored)');
+      expect(result.returnDisplay).toEqual(
+        expect.objectContaining({ summary: 'Listed 2 item(s). (2 ignored)' }),
+      );
     });
 
     it('should respect geminiignore patterns', async () => {
@@ -192,7 +205,9 @@ describe('LSTool', () => {
 
       expect(result.llmContent).toContain('file1.txt');
       expect(result.llmContent).not.toContain('file2.log');
-      expect(result.returnDisplay).toBe('Listed 2 item(s). (1 ignored)');
+      expect(result.returnDisplay).toEqual(
+        expect.objectContaining({ summary: 'Listed 2 item(s). (1 ignored)' }),
+      );
     });
 
     it('should handle non-directory paths', async () => {
@@ -203,7 +218,9 @@ describe('LSTool', () => {
       const result = await invocation.execute(abortSignal);
 
       expect(result.llmContent).toContain('Path is not a directory');
-      expect(result.returnDisplay).toBe('Error: Path is not a directory.');
+      expect(result.returnDisplay).toEqual(
+        expect.objectContaining({ summary: 'Error: Path is not a directory.' }),
+      );
       expect(result.error?.type).toBe(ToolErrorType.PATH_IS_NOT_A_DIRECTORY);
     });
 
@@ -213,7 +230,11 @@ describe('LSTool', () => {
       const result = await invocation.execute(abortSignal);
 
       expect(result.llmContent).toContain('Error listing directory');
-      expect(result.returnDisplay).toBe('Error: Failed to list directory.');
+      expect(result.returnDisplay).toEqual(
+        expect.objectContaining({
+          summary: 'Error: Failed to list directory.',
+        }),
+      );
       expect(result.error?.type).toBe(ToolErrorType.LS_EXECUTION_ERROR);
     });
 
@@ -253,7 +274,11 @@ describe('LSTool', () => {
 
       expect(result.llmContent).toContain('Error listing directory');
       expect(result.llmContent).toContain('permission denied');
-      expect(result.returnDisplay).toBe('Error: Failed to list directory.');
+      expect(result.returnDisplay).toEqual(
+        expect.objectContaining({
+          summary: 'Error: Failed to list directory.',
+        }),
+      );
       expect(result.error?.type).toBe(ToolErrorType.LS_EXECUTION_ERROR);
     });
 
@@ -279,7 +304,10 @@ describe('LSTool', () => {
       // Should still list the other files
       expect(result.llmContent).toContain('file1.txt');
       expect(result.llmContent).not.toContain('problematic.txt');
-      expect(result.returnDisplay).toBe('Listed 1 item(s).');
+      expect(result.returnDisplay).toEqual({
+        summary: 'Listed 1 item(s).',
+        files: expect.any(Array),
+      });
 
       statSpy.mockRestore();
     });
@@ -339,7 +367,10 @@ describe('LSTool', () => {
       const result = await invocation.execute(abortSignal);
 
       expect(result.llmContent).toContain('secondary-file.txt');
-      expect(result.returnDisplay).toBe('Listed 1 item(s).');
+      expect(result.returnDisplay).toEqual({
+        summary: 'Listed 1 item(s).',
+        files: expect.any(Array),
+      });
     });
   });
 });
diff --git a/packages/core/src/tools/ls.ts b/packages/core/src/tools/ls.ts
index 972c857cbd..3753ab9317 100644
--- a/packages/core/src/tools/ls.ts
+++ b/packages/core/src/tools/ls.ts
@@ -142,8 +142,10 @@ class LSToolInvocation extends BaseToolInvocation<LSToolParams, ToolResult> {
   ): ToolResult {
     return {
       llmContent,
-      // Keep returnDisplay simpler in core logic
-      returnDisplay: `Error: ${returnDisplay}`,
+      // Return an object with summary for dense output support
+      returnDisplay: {
+        summary: `Error: ${returnDisplay}`,
+      },
       error: {
         message: llmContent,
         type,
@@ -168,7 +170,9 @@ class LSToolInvocation extends BaseToolInvocation<LSToolParams, ToolResult> {
     if (validationError) {
       return {
         llmContent: validationError,
-        returnDisplay: 'Path not in workspace.',
+        returnDisplay: {
+          summary: 'Path not in workspace.',
+        },
         error: {
           message: validationError,
           type: ToolErrorType.PATH_NOT_IN_WORKSPACE,
@@ -200,7 +204,9 @@ class LSToolInvocation extends BaseToolInvocation<LSToolParams, ToolResult> {
         // Changed error message to be more neutral for LLM
         return {
           llmContent: `Directory ${resolvedDirPath} is empty.`,
-          returnDisplay: `Directory is empty.`,
+          returnDisplay: {
+            summary: `Directory is empty.`,
+          },
         };
       }
 
@@ -279,7 +285,9 @@ class LSToolInvocation extends BaseToolInvocation<LSToolParams, ToolResult> {
         llmContent: resultMessage,
         returnDisplay: {
           summary: displayMessage,
-          files: entries.map((e) => (e.isDirectory ? `${e.name}/` : e.name)),
+          files: entries.map(
+            (entry) => `${entry.isDirectory ? '[DIR] ' : ''}${entry.name}`,
+          ),
         },
       };
     } catch (error) {
diff --git a/packages/core/src/tools/read-many-files.ts b/packages/core/src/tools/read-many-files.ts
index e37caff315..85c9fecca4 100644
--- a/packages/core/src/tools/read-many-files.ts
+++ b/packages/core/src/tools/read-many-files.ts
@@ -13,6 +13,7 @@ import {
   type ToolResult,
   type PolicyUpdateOptions,
   type ToolConfirmationOutcome,
+  type ReadManyFilesResult,
 } from './tools.js';
 import { getErrorMessage } from '../utils/errors.js';
 import * as fsPromises from 'node:fs/promises';
@@ -267,7 +268,9 @@ ${finalExclusionPatternsForDescription
       const errorMessage = `Error during file search: ${getErrorMessage(error)}`;
       return {
         llmContent: errorMessage,
-        returnDisplay: `## File Search Error\n\nAn error occurred while searching for files:\n\`\`\`\n${getErrorMessage(error)}\n\`\`\``,
+        returnDisplay: {
+          summary: `Error: ${getErrorMessage(error)}`,
+        },
         error: {
           message: errorMessage,
           type: ToolErrorType.READ_MANY_FILES_SEARCH_ERROR,
@@ -462,9 +465,19 @@ ${finalExclusionPatternsForDescription
         'No files matching the criteria were found or all were skipped.',
       );
     }
+
+    const returnDisplay: ReadManyFilesResult = {
+      summary: displayMessage.trim(),
+      files: processedFilesRelativePaths,
+      skipped: skippedFiles,
+      include: this.params.include,
+      excludes: effectiveExcludes,
+      targetDir: this.config.getTargetDir(),
+    };
+
     return {
       llmContent: contentParts,
-      returnDisplay: displayMessage.trim(),
+      returnDisplay,
     };
   }
 }
diff --git a/packages/core/src/tools/ripGrep.test.ts b/packages/core/src/tools/ripGrep.test.ts
index a1b155fb7a..4481bf3e54 100644
--- a/packages/core/src/tools/ripGrep.test.ts
+++ b/packages/core/src/tools/ripGrep.test.ts
@@ -19,6 +19,7 @@ import {
   ensureRgPath,
   type RipGrepToolParams,
 } from './ripGrep.js';
+import type { GrepResult } from './tools.js';
 import path from 'node:path';
 import { isSubpath } from '../utils/paths.js';
 import fs from 'node:fs/promises';
@@ -447,7 +448,9 @@ describe('RipGrepTool', () => {
         `File: ${path.join('sub', 'fileC.txt')}`,
       );
       expect(result.llmContent).toContain('L1: another world in sub dir');
-      expect(result.returnDisplay).toBe('Found 3 matches');
+      expect((result.returnDisplay as GrepResult).summary).toBe(
+        'Found 3 matches',
+      );
     });
 
     it('should ignore matches that escape the base path', async () => {
@@ -509,7 +512,9 @@ describe('RipGrepTool', () => {
       );
       expect(result.llmContent).toContain('File: fileC.txt'); // Path relative to 'sub'
       expect(result.llmContent).toContain('L1: another world in sub dir');
-      expect(result.returnDisplay).toBe('Found 1 match');
+      expect((result.returnDisplay as GrepResult).summary).toBe(
+        'Found 1 match',
+      );
     });
 
     it('should find matches with an include glob', async () => {
@@ -542,7 +547,9 @@ describe('RipGrepTool', () => {
       expect(result.llmContent).toContain(
         'L2: function baz() { return "hello"; }',
       );
-      expect(result.returnDisplay).toBe('Found 1 match');
+      expect((result.returnDisplay as GrepResult).summary).toBe(
+        'Found 1 match',
+      );
     });
 
     it('should find matches with an include glob and path', async () => {
@@ -579,7 +586,9 @@ describe('RipGrepTool', () => {
       );
       expect(result.llmContent).toContain('File: another.js');
       expect(result.llmContent).toContain('L1: const greeting = "hello";');
-      expect(result.returnDisplay).toBe('Found 1 match');
+      expect((result.returnDisplay as GrepResult).summary).toBe(
+        'Found 1 match',
+      );
     });
 
     it('should return "No matches found" when pattern does not exist', async () => {
@@ -596,7 +605,9 @@ describe('RipGrepTool', () => {
       expect(result.llmContent).toContain(
         'No matches found for pattern "nonexistentpattern" in path ".".',
       );
-      expect(result.returnDisplay).toBe('No matches found');
+      expect((result.returnDisplay as GrepResult).summary).toBe(
+        'No matches found',
+      );
     });
 
     it('should throw error for invalid regex pattern during build', async () => {
@@ -689,7 +700,9 @@ describe('RipGrepTool', () => {
       });
       const result = await invocation.execute(abortSignal);
 
-      expect(result.returnDisplay).toContain('(limited)');
+      expect((result.returnDisplay as GrepResult).summary).toContain(
+        '(limited)',
+      );
     }, 10000);
 
     it('should filter out files based on FileDiscoveryService even if ripgrep returns them', async () => {
@@ -740,7 +753,9 @@ describe('RipGrepTool', () => {
       expect(result.llmContent).toContain('should be kept');
       expect(result.llmContent).not.toContain('ignored.txt');
       expect(result.llmContent).not.toContain('should be ignored');
-      expect(result.returnDisplay).toContain('Found 1 match');
+      expect((result.returnDisplay as GrepResult).summary).toContain(
+        'Found 1 match',
+      );
     });
 
     it('should handle regex special characters correctly', async () => {
@@ -1064,7 +1079,9 @@ describe('RipGrepTool', () => {
       controller.abort();
 
       const result = await invocation.execute(controller.signal);
-      expect(result.returnDisplay).toContain('No matches found');
+      expect((result.returnDisplay as GrepResult).summary).toContain(
+        'No matches found',
+      );
     });
   });
 
@@ -1946,7 +1963,9 @@ describe('RipGrepTool', () => {
       expect(result.llmContent).toContain('L1: match 1');
       expect(result.llmContent).toContain('L2: match 2');
       expect(result.llmContent).not.toContain('L3: match 3');
-      expect(result.returnDisplay).toBe('Found 2 matches (limited)');
+      expect((result.returnDisplay as GrepResult).summary).toBe(
+        'Found 2 matches (limited)',
+      );
     });
 
     it('should return only file paths when names_only is true', async () => {