Kinds, traits, and settings

The lines between the create header and the first blank line compose the entity. Each comma-separated term is either a kind noun or a trait, distinguished by the article: a room and a supporter are kind nouns (bundles of traits), while bare words like scenery, wearable, switchable, and light-source are individual traits.

create the workbench
  a supporter with capacity 3
  scenery
  in the Root Cellar

  A scarred oak workbench.

with attaches settings. The last token of each setting is its value and the words before it are the key (capacity 3); several settings join with and. When a keyed value is an entity name, the article marks where the name starts (feedable with food the handful of feed, where the keyword names an authored trait's data field). The built-in capability adjectives take their entity directly after with and use no keyword: lockable with the staff keycard (ratchet R3, 2026-07-18: the old key/tool keywords are load errors with fix-its).

Two trait adjectives carry a contract along with their data: cuttable and diggable. Each takes an optional implement named directly after with (cuttable with the rusty knife) that the player must be holding; with no implement named, any attempt reaches the entity. What the cut or dig actually does is never platform policy: a cuttable entity must carry exactly one implementation, an on cutting it clause, its own or from a composed trait. The story fails to load with none, or with two. The same rule binds diggable to on digging it.

create the straw bale
  aka bale, twine
  cuttable with the rusty knife
  in the Potting Shed
  states: bound, loose

  A bale of straw, bound tight with orange twine.

  on cutting it
    change it to loose
    phrase twine-cut
  end on

A trait can be conditional: while puts it under the control of a condition, live at play time.

create the Root Cellar
  a room, dark while the oil lantern is not lit
  aka cellar

  Earthen walls swallow what little light there is.

The blank line matters: composition lines come before the first blank line in the block, and prose comes after it. That rule is what keeps a description that happens to start with a trait-like word from being read as composition.