Skill: Tool renames (#296383)

* Add tool-rename-deprecation skill for legacy name backward compat

* Fix deprecated name resolution for namespaced tool references in toolsets

When a tool belongs to a toolset and has legacyToolReferenceFullNames,
the deprecated names map now includes the namespaced form (e.g.
vscode/openSimpleBrowser → vscode/openIntegratedBrowser). Previously
only the bare name was mapped, so agent files using the full
toolSet/toolName path got 'Unknown tool' instead of the rename hint.

.github/skills/tool-rename-deprecation/SKILL.md

@@ -0,0 +1,149 @@
+---
+name: tool-rename-deprecation
+description: 'Ensure renamed built-in tool references preserve backward compatibility. Use when renaming a toolReferenceName, tool set referenceName, or any tool identifier. Run on ANY change to tool registration code. Covers legacyToolReferenceFullNames for tools and legacyFullNames for tool sets.'
+---
+
+# Tool Rename Deprecation
+
+When a tool or tool set reference name is changed, the **old name must always be added to the deprecated/legacy array** so that existing prompt files, tool configurations, and saved references continue to resolve correctly.
+
+## When to Use
+
+Run this skill on **any change to built-in tool or tool set registration code** to catch regressions:
+
+- Renaming a tool's `toolReferenceName`
+- Renaming a tool set's `referenceName`
+- Moving a tool from one tool set to another (the old `toolSet/toolName` path becomes a legacy name)
+- Reviewing a PR that modifies tool registration — verify no legacy names were dropped
+
+## Procedure
+
+### Step 1 — Identify What Changed
+
+Determine whether you are renaming a **tool** or a **tool set**, and where it is registered:
+
+| Entity | Registration | Name field to rename | Legacy array | Stable ID (NEVER change) |
+|--------|-------------|---------------------|-------------|-------------------------|
+| Tool (`IToolData`) | TypeScript | `toolReferenceName` | `legacyToolReferenceFullNames` | `id` |
+| Tool (extension) | `package.json` `languageModelTools` | `toolReferenceName` | `legacyToolReferenceFullNames` | `name` (becomes `id`) |
+| Tool set (`IToolSet`) | TypeScript | `referenceName` | `legacyFullNames` | `id` |
+| Tool set (extension) | `package.json` `languageModelToolSets` | `name` or `referenceName` | `legacyFullNames` | — |
+
+**Critical:** For extension-contributed tools, the `name` field in `package.json` is mapped to `id` on `IToolData` (see `languageModelToolsContribution.ts` line `id: rawTool.name`). It is also used for activation events (`onLanguageModelTool:<name>`). **Never rename the `name` field** — only rename `toolReferenceName`.
+
+### Step 2 — Add the Old Name to the Legacy Array
+
+**Verify the old `toolReferenceName` value appears in `legacyToolReferenceFullNames`.** Don't assume it's already there — check the actual array contents. If the old name is already listed (e.g., from a previous rename), confirm it wasn't removed. If it's not there, add it.
+
+**For internal/built-in tools** (TypeScript `IToolData`):
+
+```typescript
+// Before rename
+export const MyToolData: IToolData = {
+	id: 'myExtension.myTool',
+	toolReferenceName: 'oldName',
+	// ...
+};
+
+// After rename — old name preserved
+export const MyToolData: IToolData = {
+	id: 'myExtension.myTool',
+	toolReferenceName: 'newName',
+	legacyToolReferenceFullNames: ['oldName'],
+	// ...
+};
+```
+
+If the tool previously lived inside a tool set, use the full `toolSet/toolName` form:
+
+```typescript
+legacyToolReferenceFullNames: ['oldToolSet/oldToolName'],
+```
+
+If renaming multiple times, **accumulate** all prior names — never remove existing entries:
+
+```typescript
+legacyToolReferenceFullNames: ['firstOldName', 'secondOldName'],
+```
+
+**For tool sets**, add the old name to the `legacyFullNames` option when calling `createToolSet`:
+
+```typescript
+toolsService.createToolSet(source, id, 'newSetName', {
+	legacyFullNames: ['oldSetName'],
+});
+```
+
+**For extension-contributed tools** (`package.json`), rename only `toolReferenceName` and add the old value to `legacyToolReferenceFullNames`. **Do NOT rename the `name` field:**
+
+```jsonc
+// CORRECT — only toolReferenceName changes, name stays stable
+{
+	"name": "copilot_myTool",           // ← KEEP this unchanged
+	"toolReferenceName": "newName",     // ← renamed
+	"legacyToolReferenceFullNames": [
+		"oldName"                       // ← old toolReferenceName preserved
+	]
+}
+```
+
+### Step 3 — Check All Consumers of Tool Names
+
+Legacy names must be respected **everywhere** a tool is looked up by reference name, not just in prompt resolution. Key consumers:
+
+- **Prompt files** — `getDeprecatedFullReferenceNames()` maps old → current names for `.prompt.md` validation and code actions
+- **Tool enablement** — `getToolAliases()` / `getToolSetAliases()` yield legacy names so tool picker and enablement maps resolve them
+- **Auto-approval config** — `isToolEligibleForAutoApproval()` checks `legacyToolReferenceFullNames` (including the segment after `/` for namespaced legacy names) against `chat.tools.eligibleForAutoApproval` settings
+- **RunInTerminalTool** — has its own local auto-approval check that also iterates `LEGACY_TOOL_REFERENCE_FULL_NAMES`
+
+After renaming, confirm:
+1. `#oldName` in a `.prompt.md` file still resolves (shows no validation error)
+2. Tool configurations referencing the old name still activate the tool
+3. A user who had `"chat.tools.eligibleForAutoApproval": { "oldName": false }` still has that restriction honored
+
+### Step 4 — Update References (Optional)
+
+While legacy names ensure backward compatibility, update first-party references to use the new name:
+- System prompts and built-in `.prompt.md` files
+- Documentation and model descriptions that mention the tool by reference name
+- Test files that reference the old name directly
+
+## Key Files
+
+| File | What it contains |
+|------|-----------------|
+| `src/vs/workbench/contrib/chat/common/tools/languageModelToolsService.ts` | `IToolData` and `IToolSet` interfaces with legacy name fields |
+| `src/vs/workbench/contrib/chat/browser/tools/languageModelToolsService.ts` | Resolution logic: `getToolAliases`, `getToolSetAliases`, `getDeprecatedFullReferenceNames`, `isToolEligibleForAutoApproval` |
+| `src/vs/workbench/contrib/chat/common/tools/languageModelToolsContribution.ts` | Extension point schema, validation, and the critical `id: rawTool.name` mapping (line ~274) |
+| `src/vs/workbench/contrib/terminalContrib/chatAgentTools/browser/tools/runInTerminalTool.ts` | Example of a tool with its own local auto-approval check against legacy names |
+
+## Real Examples
+
+- `runInTerminal` tool: renamed from `runCommands/runInTerminal` → `legacyToolReferenceFullNames: ['runCommands/runInTerminal']`
+- `todo` tool: renamed from `todos` → `legacyToolReferenceFullNames: ['todos']`
+- `getTaskOutput` tool: renamed from `runTasks/getTaskOutput` → `legacyToolReferenceFullNames: ['runTasks/getTaskOutput']`
+
+## Reference PRs
+
+- [#277047](https://github.com/microsoft/vscode/pull/277047) — **Design PR**: Introduced `legacyToolReferenceFullNames` and `legacyFullNames`, built the resolution infrastructure, and performed the first batch of tool renames. Use as a template for how to properly rename with legacy names.
+- [#278506](https://github.com/microsoft/vscode/pull/278506) — **Consumer-side fix**: After the renames in #277047, the `eligibleForAutoApproval` setting wasn't checking legacy names — users who had restricted the old name lost that restriction. Shows why all consumers of tool reference names must account for legacy names.
+- [vscode-copilot-chat#3810](https://github.com/microsoft/vscode-copilot-chat/pull/3810) — **Example of a miss**: Renamed `openSimpleBrowser` → `openIntegratedBrowser` but also changed the `name` field (stable id) from `copilot_openSimpleBrowser` → `copilot_openIntegratedBrowser`. The `toolReferenceName` backward compat only worked by coincidence (the old name happened to already be in the legacy array from a prior change — it was not intentionally added as part of this rename).
+
+## Regression Check
+
+Run this check on any PR that touches tool registration (TypeScript `IToolData`, `createToolSet`, or `package.json` `languageModelTools`/`languageModelToolSets`):
+
+1. **Search the diff for changed `toolReferenceName` or `referenceName` values.** For each change, confirm the **previous value** now appears in `legacyToolReferenceFullNames` or `legacyFullNames`. Don't assume it was already there — read the actual array.
+2. **Search the diff for changed `name` fields** on extension-contributed tools. The `name` field is the tool's stable `id` — it must **never** change. If it changed, flag it as a bug. (This breaks activation events, tool invocations by id, and any code referencing the tool by its `name`.)
+3. **Verify no entries were removed** from existing legacy arrays.
+4. **If a tool moved between tool sets**, confirm the old `toolSet/toolName` full path is in the legacy array.
+5. **Check tool set membership lists** (the `tools` array in `languageModelToolSets` contributions). If a tool's `toolReferenceName` changed, any tool set `tools` array referencing the old name should be updated — but the legacy resolution system handles this, so the old name still works.
+
+## Anti-patterns
+
+- **Changing the `name` field on extension-contributed tools** — the `name` in `package.json` becomes the `id` on `IToolData` (via `id: rawTool.name` in `languageModelToolsContribution.ts`). Changing it breaks activation events (`onLanguageModelTool:<name>`), any code referencing the tool by id, and tool invocations. Only rename `toolReferenceName`, never `name`. (See [vscode-copilot-chat#3810](https://github.com/microsoft/vscode-copilot-chat/pull/3810) where both `name` and `toolReferenceName` were changed.)
+- **Changing the `id` field on TypeScript-registered tools** — same principle as above. The `id` is a stable internal identifier and must never change.
+- **Assuming the old name is already in the legacy array** — always verify by reading the actual `legacyToolReferenceFullNames` contents, not just checking that the field exists. A legacy array might list names from an even older rename but not the current one being changed.
+- **Removing an old name from the legacy array** — breaks existing saved prompts and user configurations.
+- **Forgetting to add the legacy name entirely** — prompt files and tool configs silently stop resolving.
+- **Only updating prompt resolution but not other consumers** — auto-approval settings, tool enablement maps, and individual tool checks (like `RunInTerminalTool`) all need to respect legacy names (see [#278506](https://github.com/microsoft/vscode/pull/278506)).

src/vs/workbench/contrib/chat/browser/tools/languageModelToolsService.ts

@@ -1438,7 +1438,15 @@ export class LanguageModelToolsService extends Disposable implements ILanguageMo
 					add(alias, fullReferenceName);
 				}
 				if (tool.legacyToolReferenceFullNames) {
+					// If the tool is in a toolset (fullReferenceName has a '/'), also add the
+					// namespaced form of legacy names (e.g. 'vscode/oldName' → 'vscode/newName')
+					const slashIndex = fullReferenceName.lastIndexOf('/');
+					const toolSetPrefix = slashIndex !== -1 ? fullReferenceName.substring(0, slashIndex + 1) : undefined;
+
 					for (const legacyName of tool.legacyToolReferenceFullNames) {
+						if (toolSetPrefix && !legacyName.includes('/')) {
+							add(toolSetPrefix + legacyName, fullReferenceName);
+						}
 						// for any 'orphaned' toolsets (toolsets that no longer exist and
 						// do not have an explicit legacy mapping), we should
 						// just point them to the list of tools directly

src/vs/workbench/contrib/chat/test/browser/promptSyntax/languageProviders/promptValidator.test.ts

@@ -110,6 +110,11 @@ suite('PromptValidator', () => {
 		disposables.add(toolService.registerToolData(conflictTool2));
 		disposables.add(conflictToolSet2.addTool(conflictTool2));
 
+		// Tool in the vscode toolset with a legacy name — for testing namespaced deprecated name resolution
+		const toolInVscodeSet = { id: 'browserTool', toolReferenceName: 'openIntegratedBrowser', legacyToolReferenceFullNames: ['openSimpleBrowser'], displayName: 'Open Integrated Browser', canBeReferencedInPrompt: true, modelDescription: 'Open browser', source: ToolDataSource.Internal, inputSchema: {} } satisfies IToolData;
+		disposables.add(toolService.registerToolData(toolInVscodeSet));
+		disposables.add(toolService.vscodeToolSet.addTool(toolInVscodeSet));
+
 		instaService.set(ILanguageModelToolsService, toolService);
 
 		const testModels: ILanguageModelChatMetadata[] = [
@@ -500,6 +505,41 @@ suite('PromptValidator', () => {
 			assert.strictEqual(markers[0].message, expectedMessage);
 		});
 
+		test('namespaced deprecated tool name in tools header shows rename hint', async () => {
+			// When a tool is in a toolset (e.g. vscode/openIntegratedBrowser) and has a legacy name,
+			// using the namespaced old name (vscode/openSimpleBrowser) should show the rename hint
+			const content = [
+				'---',
+				'description: "Test"',
+				`tools: ['vscode/openSimpleBrowser']`,
+				'---',
+			].join('\n');
+			const markers = await validate(content, PromptsType.agent);
+			assert.deepStrictEqual(
+				markers.map(m => ({ severity: m.severity, message: m.message })),
+				[
+					{ severity: MarkerSeverity.Info, message: `Tool or toolset 'vscode/openSimpleBrowser' has been renamed, use 'vscode/openIntegratedBrowser' instead.` },
+				]
+			);
+		});
+
+		test('bare deprecated tool name in tools header also shows rename hint', async () => {
+			// The bare (non-namespaced) legacy name should also resolve
+			const content = [
+				'---',
+				'description: "Test"',
+				`tools: ['openSimpleBrowser']`,
+				'---',
+			].join('\n');
+			const markers = await validate(content, PromptsType.agent);
+			assert.deepStrictEqual(
+				markers.map(m => ({ severity: m.severity, message: m.message })),
+				[
+					{ severity: MarkerSeverity.Info, message: `Tool or toolset 'openSimpleBrowser' has been renamed, use 'vscode/openIntegratedBrowser' instead.` },
+				]
+			);
+		});
+
 		test('unknown attribute in agent file', async () => {
 			const content = [
 				'---',
@@ -1531,7 +1571,7 @@ suite('PromptValidator', () => {
 			assert.deepEqual(actual, [
 				{ message: `Unknown tool or toolset 'ms-azuretools.vscode-azure-github-copilot/azure_recommend_custom_modes'.`, startColumn: 7, endColumn: 77 },
 				{ message: `Tool or toolset 'github.vscode-pull-request-github/suggest-fix' also needs to be enabled in the header.`, startColumn: 7, endColumn: 52 },
-				{ message: `Unknown tool or toolset 'openSimpleBrowser'.`, startColumn: 7, endColumn: 24 },
+				{ message: `Tool or toolset 'openSimpleBrowser' has been renamed, use 'vscode/openIntegratedBrowser' instead.`, startColumn: 7, endColumn: 24 },
 			]);
 		});
 

src/vs/workbench/contrib/chat/test/browser/tools/languageModelToolsService.test.ts

@@ -2244,6 +2244,30 @@ suite('LanguageModelToolsService', () => {
 		assert.strictEqual(deprecatedNames.get('userToolSetRefName'), undefined);
 	});
 
+	test('getDeprecatedFullReferenceNames includes namespaced legacy names for tools in toolsets', () => {
+		// When a tool is in a toolset and has legacy names, the deprecated names map
+		// should also include the namespaced form (e.g. 'vscode/oldName' → 'vscode/newName')
+		const toolWithLegacy: IToolData = {
+			id: 'myNewBrowser',
+			toolReferenceName: 'openIntegratedBrowser',
+			legacyToolReferenceFullNames: ['openSimpleBrowser'],
+			modelDescription: 'Open browser',
+			displayName: 'Open Integrated Browser',
+			source: ToolDataSource.Internal,
+			canBeReferencedInPrompt: true,
+		};
+		store.add(service.registerToolData(toolWithLegacy));
+		store.add(service.vscodeToolSet.addTool(toolWithLegacy));
+
+		const deprecated = service.getDeprecatedFullReferenceNames();
+
+		// The simple legacy name should map to the full reference name
+		assert.deepStrictEqual(deprecated.get('openSimpleBrowser'), new Set(['vscode/openIntegratedBrowser']));
+
+		// The namespaced legacy name should also map to the full reference name
+		assert.deepStrictEqual(deprecated.get('vscode/openSimpleBrowser'), new Set(['vscode/openIntegratedBrowser']));
+	});
+
 	test('getToolByFullReferenceName', () => {
 		setupToolsForTest(service, store);