Use when authoring or debugging MPS TextGen — concept-to-plain-text serialisation for languages whose final output is text (source files, config, scripts, DDL, XML, markdown). Covers `ConceptTextGenDeclaration` roots, `append` / `indent buffer` / `with indent` statements, text layout areas, context objects (e.g. imports sets), attributes, the base text gen component (`LanguageTextGenDeclaration`), binary `write`, `found error`, and the indentation-buffer model. Reach for this skill whenever the task involves editing `<lang>/languageModels/textGen.mps`.