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. Run this skill on any change to built-in tool or tool set registration code to catch regressions: Determine whether you are renaming a tool or a tool set , and where it is registered: 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: ). Never rename the name field — only rename toolReferenceName . 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.