diff --git a/crates/aura-engine/src/construction.rs b/crates/aura-engine/src/construction.rs
index 44a07db..f601e9a 100644
--- a/crates/aura-engine/src/construction.rs
+++ b/crates/aura-engine/src/construction.rs
@@ -392,6 +392,9 @@ impl<'v> GraphSession<'v> {
             .into_iter()
             .map(|(name, source, targets)| Role { name, targets, source })
             .collect();
+        // No doc is attached here: the op-script vocabulary deliberately has no
+        // doc-carrying surface yet (#125 scope cut) — an op-built composite
+        // carries no authored rationale until that vocabulary grows a slot.
         let c = Composite::new(self.name, self.nodes, self.edges, roles, self.out)
             .with_gangs(self.gangs)
             .map_err(OpError::Incomplete)?;
diff --git a/docs/design/INDEX.md b/docs/design/INDEX.md
index 78e66c9..d8adcd0 100644
--- a/docs/design/INDEX.md
+++ b/docs/design/INDEX.md
@@ -378,6 +378,21 @@ and params and across both graph levels. This does **not** close #21 (a swapped
 same-kind wiring is still only kind-checked) — it makes those slots
 self-documenting; a name-consuming validation is its own future cycle.
 
+**Realization (2026-07-11 — composite `doc`, #125).** `Composite` carries an
+optional authored rationale `doc: Option<String>` — the prose twin of its `name`
+and the same C23 category: a non-load-bearing debug symbol. Authored via
+`Composite::with_doc` / `GraphBuilder::doc`; persisted as a Tier-1
+additive-optional `CompositeData` field (no format-version bump; absent-field
+documents keep their exact bytes, so existing content ids are untouched);
+**blanked in the identity projection** (`strip_debug_symbols`) while staying
+canonical-byte-bearing; dissolved at inline like the name (never reaches
+`FlatGraph`). Surfaced read-only (C22): the graph model emits an optional
+trailing `"doc"` fragment per scope (`json_str` hardened for multi-line free
+text — `\n`/`\t`/`\r` named, other control chars as `\u00XX`), the viewer shows
+it in both composite view states (collapsed tooltip, expanded cluster frame) and
+the root's as a muted header line. The construction op-script vocabulary
+deliberately has no doc-carrying surface yet (scope cut recorded on #125).
+
 **Realization (cycle 0040 — wiring totality: every input slot connected exactly
 once, #65).** The node contract's "the engine provides a window into each input"
 presupposes each input is actually fed; until now an unwired interior input slot was
@@ -1888,7 +1903,13 @@ pip (resolved from the recorded geometry sidecar (`instrument_geometry`) — C10
 refuse-don't-guess; a symbol with no recorded geometry exits 2 before any data
 access), window, and — for walk-forward — its `WindowRoller` sizes
 (synthetic: bar-index 24/12/12; real: fixed calendar-time 90d/30d/30d in ns; CLI
-flags for these are deferred). The engine, ingest, and registry are untouched (C9 —
+flags for these are deferred). **[Amended 2026-07-11 (#239): on the dissolved
+`walkforward --real`/`mc --real` sugar path the fixed 90/30/30 sizes are a
+*ceiling*, not a constant — `fit_wf_ms_sizes` (aura-cli) passes them through
+byte-identically whenever they fit the resolved campaign window, and scales them
+down preserving the 3:1 IS:OOS ratio (step = OOS, one roll at the minimum) when
+the window is shorter; authored process documents still validate their declared
+sizes as-is.]** The engine, ingest, and registry are untouched (C9 —
 the whole change is in `aura-cli`); the synthetic path is byte-unchanged.
 **MC is excluded** (#106 Fork A): its seed varies a *synthetic* price-walk
 realization (C12 axis 4), which is undefined over real data's single realization —
diff --git a/docs/glossary.md b/docs/glossary.md
index b4fe71c..4f2820b 100644
--- a/docs/glossary.md
+++ b/docs/glossary.md
@@ -61,7 +61,7 @@ The type-erased 64-bit word holding one scalar-base-type value with its kind str
 
 ### composite
 **Avoid:** —
-A node that wires a sub-graph and exposes one output (a combined signal, or a strategy) — composition is fractal and acyclic. Also names the multi-column stream a node emits: the **record** a producer's `eval` returns, bundling 1..K base scalar columns (e.g. OHLCV), each bound field-wise by a consumer (C7/C8).
+A node that wires a sub-graph and exposes one output (a combined signal, or a strategy) — composition is fractal and acyclic. May carry an optional authored rationale (`doc`, #125) — a non-load-bearing debug symbol shown in the graph tooltip, identity-blind like the name. Also names the multi-column stream a node emits: the **record** a producer's `eval` returns, bundling 1..K base scalar columns (e.g. OHLCV), each bound field-wise by a consumer (C7/C8).
 
 ### content id
 **Avoid:** —
@@ -143,7 +143,7 @@ The authoring-loop mechanism in which the project-side cdylib is rebuilt and rel
 
 ### identity id
 **Avoid:** identity hash, topology-identity hash
-The SHA-256 of a blueprint's identity-canonical form (`blueprint_identity_json`: the canonical document with every non-load-bearing debug symbol blanked — composite, instance, bound-param, role, and output names), surfaced as `aura graph introspect --identity-id`. Same topology → same id across authoring paths (op-script vs Rust builder, renamed twins) while openness, bound values, wiring, and order stay identity-bearing; an introspection-only comparison id — the byte-exact `content id` keeps the store/reproduce roles.
+The SHA-256 of a blueprint's identity-canonical form (`blueprint_identity_json`: the canonical document with every non-load-bearing debug symbol blanked — composite, instance, bound-param, role, and output names, and the composite `doc`), surfaced as `aura graph introspect --identity-id`. Same topology → same id across authoring paths (op-script vs Rust builder, renamed twins) while openness, bound values, wiring, and order stay identity-bearing; an introspection-only comparison id — the byte-exact `content id` keeps the store/reproduce roles.
 
 ### ingestion boundary
 **Avoid:** —