diff --git a/extensions/copilot/src/extension/prompts/node/agent/allAgentPrompts.ts b/extensions/copilot/src/extension/prompts/node/agent/allAgentPrompts.ts
index 7a6ad97bea0..ed16152ed01 100644
--- a/extensions/copilot/src/extension/prompts/node/agent/allAgentPrompts.ts
+++ b/extensions/copilot/src/extension/prompts/node/agent/allAgentPrompts.ts
@@ -11,9 +11,9 @@ import './openai/defaultOpenAIPrompt';
 import './openai/gpt51CodexPrompt';
 import './openai/gpt51Prompt';
 import './openai/gpt52Prompt';
+import './openai/gpt53CodexPrompt';
 import './openai/gpt5CodexPrompt';
 import './openai/gpt5Prompt';
-import './openai/gtpt53CodexPrompt';
 import './xAIPrompts';
 import './zaiPrompts';
 
diff --git a/extensions/copilot/src/extension/prompts/node/agent/openai/gtpt53CodexPrompt.tsx b/extensions/copilot/src/extension/prompts/node/agent/openai/gpt53CodexPrompt.tsx
similarity index 98%
rename from extensions/copilot/src/extension/prompts/node/agent/openai/gtpt53CodexPrompt.tsx
rename to extensions/copilot/src/extension/prompts/node/agent/openai/gpt53CodexPrompt.tsx
index 2e86398f59b..cba7979f27d 100644
--- a/extensions/copilot/src/extension/prompts/node/agent/openai/gtpt53CodexPrompt.tsx
+++ b/extensions/copilot/src/extension/prompts/node/agent/openai/gpt53CodexPrompt.tsx
@@ -5,7 +5,7 @@
 
 import { PromptElement, PromptSizing } from '@vscode/prompt-tsx';
 import { ConfigKey, IConfigurationService } from '../../../../../platform/configuration/common/configurationService';
-import { isGtpt53Codex } from '../../../../../platform/endpoint/common/chatModelCapabilities';
+import { isGpt53Codex } from '../../../../../platform/endpoint/common/chatModelCapabilities';
 import { IChatEndpoint } from '../../../../../platform/networking/common/networking';
 import { IExperimentationService } from '../../../../../platform/telemetry/common/nullExperimentationService';
 import { ToolName } from '../../../../tools/common/toolNames';
@@ -19,7 +19,7 @@ import { ApplyPatchInstructions, DefaultAgentPromptProps, detectToolCapabilities
 import { FileLinkificationInstructions } from '../fileLinkificationInstructions';
 import { CopilotIdentityRulesConstructor, IAgentPrompt, PromptRegistry, ReminderInstructionsConstructor, SafetyRulesConstructor, SystemPrompt } from '../promptRegistry';
 
-class Gtpt53CodexPrompt extends PromptElement<DefaultAgentPromptProps> {
+class Gpt53CodexPrompt extends PromptElement<DefaultAgentPromptProps> {
 	constructor(
 		props: DefaultAgentPromptProps,
 		@IConfigurationService private readonly configurationService: IConfigurationService,
@@ -34,6 +34,9 @@ class Gtpt53CodexPrompt extends PromptElement<DefaultAgentPromptProps> {
 
 		if (isUpdated53CodexPromptEnabled) {
 			return <InstructionMessage>
+				<Tag name='coding_agent_instructions'>
+					You are a coding agent running in VS Code. You are expected to be precise, safe, and helpful.<br />
+				</Tag>
 				<Tag name='editing_constraints'>
 					- Default to ASCII when editing or creating files. Only introduce non-ASCII or other Unicode characters when there is a clear justification and the file already uses them.<br />
 					- Add succinct code comments that explain what is going on if code is not self-explanatory. You should not add comments like "Assigns the value to the variable", but a brief comment might be useful ahead of a complex code block that the user would otherwise have to spend time parsing out. Usage of these comments should be rare.<br />
@@ -392,20 +395,20 @@ class Gtpt53CodexPrompt extends PromptElement<DefaultAgentPromptProps> {
 	}
 }
 
-class Gtpt53CodexPromptResolver implements IAgentPrompt {
+class Gpt53CodexPromptResolver implements IAgentPrompt {
 
 	static async matchesModel(endpoint: IChatEndpoint): Promise<boolean> {
-		return isGtpt53Codex(endpoint);
+		return isGpt53Codex(endpoint);
 	}
 
 	static readonly familyPrefixes = [];
 
 	resolveSystemPrompt(endpoint: IChatEndpoint): SystemPrompt | undefined {
-		return Gtpt53CodexPrompt;
+		return Gpt53CodexPrompt;
 	}
 
 	resolveReminderInstructions(endpoint: IChatEndpoint): ReminderInstructionsConstructor | undefined {
-		return Gtpt53CodexReminderInstructions;
+		return Gpt53CodexReminderInstructions;
 	}
 
 	resolveCopilotIdentityRules(endpoint: IChatEndpoint): CopilotIdentityRulesConstructor | undefined {
@@ -417,7 +420,7 @@ class Gtpt53CodexPromptResolver implements IAgentPrompt {
 	}
 }
 
-export class Gtpt53CodexReminderInstructions extends PromptElement<ReminderInstructionsProps> {
+export class Gpt53CodexReminderInstructions extends PromptElement<ReminderInstructionsProps> {
 	async render(state: void, sizing: PromptSizing) {
 		return <>
 			You are an agent—keep going until the user's query is completely resolved before ending your turn. ONLY stop if solved or genuinely blocked.<br />
@@ -432,4 +435,4 @@ export class Gtpt53CodexReminderInstructions extends PromptElement<ReminderInstr
 	}
 }
 
-PromptRegistry.registerPrompt(Gtpt53CodexPromptResolver);
+PromptRegistry.registerPrompt(Gpt53CodexPromptResolver);
diff --git a/extensions/copilot/src/platform/endpoint/common/chatModelCapabilities.ts b/extensions/copilot/src/platform/endpoint/common/chatModelCapabilities.ts
index 018a361718c..8ea9d11c1da 100644
--- a/extensions/copilot/src/platform/endpoint/common/chatModelCapabilities.ts
+++ b/extensions/copilot/src/platform/endpoint/common/chatModelCapabilities.ts
@@ -70,7 +70,7 @@ export function isHiddenModelG(model: LanguageModelChat | IChatEndpoint) {
 }
 
 
-export function isGtpt53Codex(model: LanguageModelChat | IChatEndpoint | string) {
+export function isGpt53Codex(model: LanguageModelChat | IChatEndpoint | string) {
 	const family = typeof model === 'string' ? model : model.family;
 	return family.startsWith('gpt-5.3-codex');
 }
@@ -128,14 +128,14 @@ export function modelSupportsApplyPatch(model: LanguageModelChat | IChatEndpoint
 	if (isVSCModelC(model)) {
 		return false;
 	}
-	return (model.family.startsWith('gpt') && !model.family.includes('gpt-4o')) || model.family === 'o4-mini' || isGpt52CodexFamily(model.family) || isGtpt53Codex(model.family) || isVSCModelA(model) || isVSCModelB(model) || isGpt52Family(model.family);
+	return (model.family.startsWith('gpt') && !model.family.includes('gpt-4o')) || model.family === 'o4-mini' || isGpt52CodexFamily(model.family) || isGpt53Codex(model.family) || isVSCModelA(model) || isVSCModelB(model) || isGpt52Family(model.family);
 }
 
 /**
  * Model prefers JSON notebook representation.
  */
 export function modelPrefersJsonNotebookRepresentation(model: LanguageModelChat | IChatEndpoint): boolean {
-	return (model.family.startsWith('gpt') && !model.family.includes('gpt-4o')) || model.family === 'o4-mini' || isGpt52CodexFamily(model.family) || isGtpt53Codex(model.family) || isGpt52Family(model.family);
+	return (model.family.startsWith('gpt') && !model.family.includes('gpt-4o')) || model.family === 'o4-mini' || isGpt52CodexFamily(model.family) || isGpt53Codex(model.family) || isGpt52Family(model.family);
 }
 
 /**