don't show shimmer for things that shouldn't shimmer

src/vs/workbench/contrib/chat/browser/widget/chatContentParts/toolInvocationParts/chatToolPartUtilities.ts

@@ -17,7 +17,7 @@ export function isMcpToolInvocation(toolInvocation: IChatToolInvocation | IChatT
  */
 export function shouldShimmerForTool(toolInvocation: IChatToolInvocation | IChatToolInvocationSerialized): boolean {
 	if (isMcpToolInvocation(toolInvocation)) {
-		return true;
+		return !IChatToolInvocation.isComplete(toolInvocation);
 	}
 	if (toolInvocation.toolId === 'copilot_askQuestions' || toolInvocation.toolId === 'vscode_askQuestions') {
 		return false;

src/vs/workbench/contrib/chat/browser/widget/chatListRenderer.ts

@@ -1025,6 +1025,11 @@ export class ChatListItemRenderer extends Disposable implements ITreeRenderer<Ch
 			return false;
 		}
 
+		// Don't show working spinner when there's an in-progress MCP tool - MCP tools have their own progress indicator
+		if (partsToRender.some(part => part.kind === 'toolInvocation' && !IChatToolInvocation.isComplete(part) && isMcpToolInvocation(part))) {
+			return false;
+		}
+
 		// Show if no content, only "used references", ends with a complete tool call, or ends with complete text edits and there is no incomplete tool call (edits are still being applied some time after they are all generated)
 		const lastPart = findLast(partsToRender, part => part.kind !== 'markdownContent' || part.content.value.trim().length > 0);
 

src/vs/workbench/contrib/chat/test/browser/widget/chatContentParts/chatToolProgressPart.test.ts

@@ -182,7 +182,7 @@ suite('ChatToolProgressSubPart', () => {
 	});
 
 	test('adds shimmer styling for active MCP tool progress', () => {
-		const mcpTool = createSerializedToolInvocation({
+		const mcpTool = createToolInvocation({
 			source: {
 				type: 'mcp',
 				label: 'Weather MCP',
@@ -221,4 +221,28 @@ suite('ChatToolProgressSubPart', () => {
 
 		assert.strictEqual(part.domNode.querySelector('.shimmer-progress'), null);
 	});
+
+	test('does not add shimmer styling for completed MCP tool progress', () => {
+		const mcpTool = createSerializedToolInvocation({
+			source: {
+				type: 'mcp',
+				label: 'Weather MCP',
+				serverLabel: 'Weather',
+				instructions: undefined,
+				collectionId: 'collection',
+				definitionId: 'definition'
+			},
+			toolId: 'weather_lookup'
+		});
+
+		const part = disposables.add(instantiationService.createInstance(
+			ChatToolProgressSubPart,
+			mcpTool,
+			createRenderContext(false),
+			mockMarkdownRenderer,
+			new Set<string>()
+		));
+
+		assert.strictEqual(part.domNode.querySelector('.shimmer-progress'), null);
+	});
 });