diff --git a/TODO b/TODO
index e38adfbb..d97d8e49 100644
--- a/TODO
+++ b/TODO
@@ -15,7 +15,11 @@ Working TODO list:
    - improved error handling:
      - param count checks
        * should have checks in compiler as well. could possibly
-         use prim metadata to autogenerate the runtime checks (later, perhaps)
+         use prim metadata to autogenerate the runtime checks (later, perhaps).
+         absolutely need this, but  may require some thought. which phase should
+         do the checks? also may require looking at lib files because you need
+         to check each application point, and need to look up the function to
+         see how many args it can receive.
      - type checking
        ideally want to do this in a way that minimized performance impacts.
        will probaby require extensive checks within apply() though, since that