Improvements and perspective from architecture review

workplans/MKTT-WP-0012-document-function-layer.md

@@ -45,7 +45,9 @@ Implemented the first deterministic document function layer:
 - Conservative fenced syntax: `mkt-function function.name ...`.
 - Pipeline chaining with `|`, where the previous result becomes the next
   function's first argument.
+- Quoted `|` characters remain literal inside function arguments.
 - `ProcessingContext.variables` bindings through `${name}` values.
+- Validation reports unknown or duplicate named arguments before execution.
 - Built-in deterministic functions for text operations, Markdown headings,
   bold text, links, code blocks, and context value lookup.
 - `mkt function list`, `mkt function check`, and `mkt function render`.
@@ -53,9 +55,10 @@ Implemented the first deterministic document function layer:
 - Documentation and examples in `docs/document-functions.md` and
   `examples/functions/basic-functions.md`.
 
-Assisted, filesystem, network, external-process, render/export, and live policy
-service functions remain future optional extensions gated by local capability
-and policy metadata.
+Assisted, filesystem, network, external-process, render/export, typed-value,
+asset, and live policy service functions remain future optional extensions
+gated by local capability and policy metadata. The follow-on extension track is
+captured in `MKTT-WP-0015`.
 
 ## Background