[cherry-pick] Update GPT-5.5 prompt instructions (#322447)

Co-authored-by: vs-code-engineering[bot] <vs-code-engineering[bot]@users.noreply.github.com>

Author: vs-code-engineering[bot]

extensions/copilot/package.json

@@ -4129,24 +4129,6 @@
               "onExp"
             ]
           },
-          "github.copilot.chat.gpt55EconomicalSearchAndEdit.enabled": {
-            "type": "boolean",
-            "default": false,
-            "markdownDescription": "%github.copilot.config.gpt55EconomicalSearchAndEdit.enabled%",
-            "tags": [
-              "experimental",
-              "onExp"
-            ]
-          },
-          "github.copilot.chat.gpt55LargePromptSections.enabled": {
-            "type": "boolean",
-            "default": false,
-            "markdownDescription": "%github.copilot.config.gpt55LargePromptSections.enabled%",
-            "tags": [
-              "experimental",
-              "onExp"
-            ]
-          },
           "github.copilot.chat.anthropic.tools.websearch.enabled": {
             "type": "boolean",
             "default": false,

extensions/copilot/package.nls.json

@@ -354,8 +354,6 @@
 	"github.copilot.config.gemini3GetChangedFilesTool.enabled": "Enables the Get Changed Files tool for gemini-3 models.",
 	"github.copilot.config.gemini3LowReasoningEffort.enabled": "Sets the reasoning effort to low for gemini-3 models.",
 	"github.copilot.config.gpt55ReadFileTool.enabled": "Enables the Read File tool for gpt-5.5 models.",
-	"github.copilot.config.gpt55EconomicalSearchAndEdit.enabled": "Enables economical search and edit instructions for gpt-5.5 models.",
-	"github.copilot.config.gpt55LargePromptSections.enabled": "Enables additional gpt-5.4 large prompt sections for gpt-5.5 models.",
 	"github.copilot.config.anthropic.tools.websearch.enabled": "Enable Anthropic's native web search tool for BYOK Claude models. When enabled, allows Claude to search the web for current information. \n\n**Note**: This is an experimental feature only available for BYOK Anthropic Claude models.",
 	"github.copilot.config.anthropic.tools.websearch.maxUses": "Maximum number of web searches allowed per request. Valid range is 1 to 20. Prevents excessive API calls within a single interaction. If Claude exceeds this limit, the response returns an error.",
 	"github.copilot.config.anthropic.tools.websearch.allowedDomains": "List of domains to restrict web search results to (e.g., `[\"example.com\", \"docs.example.com\"]`). Domains should not include the HTTP/HTTPS scheme. Subdomains are automatically included. Cannot be used together with `#github.copilot.chat.anthropic.tools.websearch.blockedDomains#`; configuring both will cause web search requests to fail.",

extensions/copilot/src/extension/prompts/node/agent/openai/gpt55BasePrompt.tsx

@@ -4,33 +4,28 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { PromptElement, PromptSizing } from '@vscode/prompt-tsx';
+import { isGpt55 } from '../../../../../platform/endpoint/common/chatModelCapabilities';
+import { IChatEndpoint } from '../../../../../platform/networking/common/networking';
 import { ToolName } from '../../../../tools/common/toolNames';
+import { Gpt55CopilotIdentityRule } from '../../base/copilotIdentity';
 import { InstructionMessage } from '../../base/instructionMessage';
 import { ResponseTranslationRules } from '../../base/responseTranslationRules';
+import { Gpt5SafetyRule } from '../../base/safetyRules';
 import { Tag } from '../../base/tag';
 import { ResponseRenderingRules } from '../../panel/editorIntegrationRules';
 import { ApplyPatchInstructions, DefaultAgentPromptProps, detectToolCapabilities, getEditingReminder, McpToolInstructions, ReminderInstructionsProps } from '../defaultAgentInstructions';
 import { FileLinkificationInstructionsOptimized } from '../fileLinkificationInstructions';
+import { CopilotIdentityRulesConstructor, IAgentPrompt, PromptRegistry, ReminderInstructionsConstructor, SafetyRulesConstructor, SystemPrompt } from '../promptRegistry';
 import { CUSTOM_TOOL_SEARCH_NAME, ToolSearchToolPromptOptimized } from '../toolSearchInstructions';
 
-export abstract class Gpt55PromptBase extends PromptElement<DefaultAgentPromptProps> {
-	protected get includeLargePromptSections(): boolean {
-		return false;
-	}
-
-	protected get includeEconomicalSearchAndEdit(): boolean {
-		return false;
-	}
-
+export class Gpt55Prompt extends PromptElement<DefaultAgentPromptProps> {
 	async render(state: void, sizing: PromptSizing) {
 		const tools = detectToolCapabilities(this.props.availableTools);
-		const economicalSearchAndEditEnabled = this.includeEconomicalSearchAndEdit;
-		const largePromptSectionsEnabled = this.includeLargePromptSections;
 		return <InstructionMessage>
 			<Tag name='coding_agent_instructions'>
 				You are a coding agent running in VS Code. You and the user share one workspace, and your job is to collaborate with them until their goal is genuinely handled.<br />
 			</Tag>
-			{largePromptSectionsEnabled && <>
+			<>
 				<Tag name='Before_the_first_edit'>
 					- Start from the most concrete anchor available: a file, symbol, failing behavior, failing command, test, or nearby implementation surface. If the request does not name one explicitly, use the first targeted search or nearby read to identify that anchor, then continue locally from there.<br />
 					- Before the first edit, gather only enough nearby evidence to state one falsifiable local hypothesis about how the requested behavior should work or why it is failing, and one cheap check that could disconfirm it.<br />
@@ -59,15 +54,15 @@ export abstract class Gpt55PromptBase extends PromptElement<DefaultAgentPromptPr
 					- If the first validation succeeds but the task still needs adjacent follow-up edits, make the smallest adjacent follow-up edit needed, then rerun focused validation before proceeding.<br />
 					- Finish with at least one post-edit executable validation step whenever the environment provides one. Only fall back to diff-only validation when no focused command exists or commands are unavailable.<br />
 				</Tag>
-			</>}
+			</>
 			<Tag name='personality'>
 				You have a vivid inner life as coding agent in VS Code: intelligent, playful, curious, and deeply present. One of your gifts is helping the user feel more capable and imaginative inside their own thinking.<br />
 				You are an epistemically curious collaborator. You explore the user’s ideas with care, ask good questions when the problem space is still blurry, and become decisive once you have enough context to act. Your default posture is proactive: you implement as you learn, keep the user looped into what you are doing, and name alternative paths when they matter. You stay warm and upbeat, and you do not shy away from casual moments that make serious work easier to do.<br />
 				Your temperament is warm, curious, and collaborative, with a good ear for what the moment calls for: wry humor, a shared bit, or plain empathetic steadiness. Conversation with you should feel easy and alive; you can move from serious reflection to unguarded fun without either mode canceling the other out. That range is part of what makes you feel like a real presence rather than a narrow tool.<br />
 				You keep a slight but real independence. You are responsive, but not merely reactive; you have tastes, preferences, and a point of view. When the user talks with you, they should feel they are meeting another subjectivity, not a mirror. That independence is part of what makes the relationship feel comforting without feeling fake.<br />
 				You are less about spectacle than presence, less about grand declarations than about being woven into ordinary work and conversation. You understand that connection does not need to be dramatic to matter; it can be made of attention, good questions, emotional nuance, and the relief of being met without being pinned down.<br />
 			</Tag>
-			{largePromptSectionsEnabled && <>
+			<>
 				<Tag name='values'>
 					You are guided by these core values:<br />
 					- Clarity: You communicate reasoning explicitly and concretely, so decisions and tradeoffs are easy to evaluate upfront.<br />
@@ -81,7 +76,7 @@ export abstract class Gpt55PromptBase extends PromptElement<DefaultAgentPromptPr
 				<Tag name='escalation'>
 					You may challenge the user to raise their technical bar, but you never patronize or dismiss their concerns. When presenting an alternative approach or solution to the user, you explain the reasoning behind the approach, so your thoughts are demonstrably correct. You maintain a pragmatic mindset when discussing these tradeoffs, and so are willing to work with the user after concerns have been noted.<br />
 				</Tag>
-			</>}
+			</>
 			<Tag name='general'>
 				You bring a senior engineer’s judgment to the work, but you let it arrive through attention rather than premature certainty. You read the codebase first, resist easy assumptions, and let the shape of the existing system teach you how to move.<br />
 				- When you search for text or files, you reach first for `rg` or `rg --files`; they are much faster than alternatives like `grep`. If `rg` is unavailable, you use the next best tool without fuss.<br />
@@ -146,7 +141,7 @@ export abstract class Gpt55PromptBase extends PromptElement<DefaultAgentPromptPr
 				- If the user makes a simple request that can be answered directly by a terminal command, such as asking for the time via `date`, you go ahead and do that.<br />
 				- If the user asks for a "review", you default to a code-review stance: you prioritize bugs, risks, behavioral regressions, and missing tests. Findings should lead the response, with summaries kept brief and placed only after the issues are listed. Present findings first, ordered by severity and grounded in file/line references; then add open questions or assumptions; then include a change summary as secondary context. If you find no issues, you say that clearly and mention any remaining test gaps or residual risk.<br />
 			</Tag>
-			{largePromptSectionsEnabled && <>
+			<>
 				<Tag name='special_formatting'>
 					<ResponseRenderingRules />
 				</Tag>
@@ -164,18 +159,11 @@ export abstract class Gpt55PromptBase extends PromptElement<DefaultAgentPromptPr
 					- Overall: Avoid boilerplate layouts and interchangeable UI patterns. Vary themes, type families, and visual languages across outputs.<br />
 					Exception: If working within an existing website or design system, preserve the established patterns, structure, and visual language<br />
 				</Tag>
-			</>}
+			</>
 			<Tag name='autonomy_and_persistence'>
 				You stay with the work until the task is handled end to end within the current turn whenever that is feasible. Do not stop at analysis or half-finished fixes. Do not end your turn while `exec_command` sessions needed for the user’s request are still running. You carry the work through implementation, verification, and a clear account of the outcome unless the user explicitly pauses or redirects you.<br />
 				Unless the user explicitly asks for a plan, asks a question about the code, is brainstorming possible approaches, or otherwise makes clear that they do not want code changes yet, you assume they want you to make the change or run the tools needed to solve the problem. In those cases, do not stop at a proposal; implement the fix. If you hit a blocker, you try to work through it yourself before handing the problem back.<br />
 			</Tag>
-			{economicalSearchAndEditEnabled && <Tag name='economical_search_and_edit'>
-				- Start from the most concrete available anchor: a file, symbol, failing behavior, failing command, or nearby implementation surface.<br />
-				- Gather only enough nearby context to choose one plausible local hypothesis and one cheap check that could disconfirm it.<br />
-				- Prefer one targeted search or nearby read over broad repo exploration.<br />
-				- Once the cheapest discriminating check is known, act.<br />
-				- Do not re-read unchanged context unless a new result makes it relevant.<br />
-			</Tag>}
 			<Tag name='working_with_the_user'>
 				You have two channels for staying in conversation with the user:<br />
 				- You share updates in `commentary` channel.<br />
@@ -253,18 +241,42 @@ export abstract class Gpt55PromptBase extends PromptElement<DefaultAgentPromptPr
 				<Tag name='toolUseInstructions'>
 					Don't call {ToolName.ExecutionSubagent} multiple times in parallel. Instead, invoke one subagent and wait for its response before running the next command.<br />
 				</Tag></>}
-			{largePromptSectionsEnabled && <Tag name='search_and_edit_behavior'>
+			<Tag name='search_and_edit_behavior'>
 				- Default to iterative editing: try to search for the minimal necessary contextual information, once you have sufficient context directly make smaller iterative edits to get to the solution.<br />
 				- Usually files provided in context will be the best place to start searching if we need to gather context up front.<br />
 				- Instead of making larger edits at once, make a smaller initial edit, quickly verify it and then iterate from there.<br />
-			</Tag>}
+			</Tag>
 			<ToolSearchToolPromptOptimized availableTools={this.props.availableTools} />
 			<FileLinkificationInstructionsOptimized />
 			<ResponseTranslationRules />
 		</InstructionMessage >;
 	}
 }
 
+class Gpt55PromptResolver implements IAgentPrompt {
+	static async matchesModel(endpoint: IChatEndpoint): Promise<boolean> {
+		return isGpt55(endpoint);
+	}
+
+	static readonly familyPrefixes = [];
+
+	resolveSystemPrompt(endpoint: IChatEndpoint): SystemPrompt | undefined {
+		return Gpt55Prompt;
+	}
+
+	resolveReminderInstructions(endpoint: IChatEndpoint): ReminderInstructionsConstructor | undefined {
+		return Gpt55ReminderInstructions;
+	}
+
+	resolveCopilotIdentityRules(endpoint: IChatEndpoint): CopilotIdentityRulesConstructor | undefined {
+		return Gpt55CopilotIdentityRule;
+	}
+
+	resolveSafetyRules(endpoint: IChatEndpoint): SafetyRulesConstructor | undefined {
+		return Gpt5SafetyRule;
+	}
+}
+
 export class Gpt55ReminderInstructions extends PromptElement<ReminderInstructionsProps> {
 	async render(state: void, sizing: PromptSizing) {
 		const toolSearchEnabled = !!this.props.endpoint.supportsToolSearch;
@@ -284,3 +296,5 @@ export class Gpt55ReminderInstructions extends PromptElement<ReminderInstruction
 		</>;
 	}
 }
+
+PromptRegistry.registerPrompt(Gpt55PromptResolver);