diff --git a/.changeset/30893-bare-field-ref-symptom.md b/.changeset/30893-bare-field-ref-symptom.md
new file mode 100644
index 00000000000..6c2b76d10ab
--- /dev/null
+++ b/.changeset/30893-bare-field-ref-symptom.md
@@ -0,0 +1,10 @@
+---
+'@objectstack/skills': patch
+---
+
+docs(skills): three skills describe a bare field ref in a predicate as the fault it is today, not a silent `null`
+
+Clause-②: no
+Metadata-protocol: none
+
+`objectstack-platform/references/operations.md`, `objectstack-data` and `objectstack-ui` said a bare field ref (`done` instead of `record.done`) "evaluates to `null`" and silently hides or never fires. It faults. On the server an `error` validation rule and a `requiredWhen` refuse the write and name the rule, an option `visibleWhen` refuses only a write that picks that option (forms still offer it), a `readonlyWhen` field stays editable on the form while the server drops the change with a warning and the save succeeds, and a formula reads `null` with a logged warning. In the console an action's `visible` hides it, its `disabled` greys it out, and a field `visibleWhen` shows the field, each with a console warning. The data skill no longer lists RLS / sharing predicates here: their compiler reads a bare name as the column. The prevention advice (`os validate` / `os build`, `record.<field>`) is unchanged. Growth is paid by same-file deletions of restated prose.
diff --git a/skills/objectstack-data/SKILL.md b/skills/objectstack-data/SKILL.md
index 64855998ebc..c75cdee23fc 100644
--- a/skills/objectstack-data/SKILL.md
+++ b/skills/objectstack-data/SKILL.md
@@ -202,7 +202,7 @@ export const Invoice = ObjectSchema.create({
   set → field permission `when`, rules/security.md).
 - **`readonly: true` governs the end-user surface, not trusted system writers.**
   A non-system write (REST/UI, and any `runAs:'user'` flow — the default) has
-  the field **stripped** from any non-system write; the write reports
+  the field **stripped**; the write reports
   success but the value never lands. System-context writes —
   `runAs:'system'` flows, system hooks, seeds, imports, migrations — are exempt
   and DO write it. So the pattern "users can't edit this, but automation
@@ -447,13 +447,15 @@ os validate     # Zod schema + CEL predicates (record.<field> existence) + bindi
 # or: os build  # the same gates, plus emits dist/
 ```
 
-It catches what otherwise fails **silently at runtime**: a bare field ref in a
-`requiredWhen` / `readonlyWhen` / `visibleWhen`, a validation rule, a formula, or
-a row-level-security/sharing predicate (`done` instead of `record.done`) that
-evaluates to `null` and never fires. `os lint` is a *separate*
+It catches what otherwise surfaces only at runtime, where a bare field ref
+(`done` for `record.done`) faults: an `error` validation rule or `requiredWhen`
+refuses the write naming it, an option `visibleWhen` only a write picking the
+option (forms still offer it); a `readonlyWhen` field stays editable and the
+save succeeds without its change (logged); a formula reads `null` (logged).
+`os lint` is a *separate*
 pass that additionally checks the data model against the conventions in this
-skill (relationships, master-detail, roll-ups) — run it too, but it does **not**
-replace `os validate`. In a scaffolded project the gate is `npm run validate`.
+skill (relationships, master-detail, roll-ups) — run it too.
+In a scaffolded project the gate is `npm run validate`.
 
 ---
 
diff --git a/skills/objectstack-platform/references/operations.md b/skills/objectstack-platform/references/operations.md
index 57944ff920b..40fc22b0a56 100644
--- a/skills/objectstack-platform/references/operations.md
+++ b/skills/objectstack-platform/references/operations.md
@@ -24,11 +24,11 @@
 
 ## Verify your work
 
-ObjectStack metadata mistakes fail **silently at runtime**, not at edit time:
-a bare field ref in a predicate (`done` instead of `record.done`) evaluates to
-`null` and silently hides an action/validation on every record; a
-dangling dashboard widget binding renders an empty chart (ADR-0021). Both are
-caught at author time by one command:
+Metadata mistakes surface at runtime, not at edit time: a bare field ref in a
+predicate (`done` for `record.done`) faults, so an `error` validation rule
+refuses each write naming the rule and an action's `visible` hides it; a
+dangling dashboard widget binding renders an empty chart. Both are caught at
+author time by one command:
 
 ```bash
 os validate     # Zod schema + CEL predicates + widget bindings — no artifact
diff --git a/skills/objectstack-ui/SKILL.md b/skills/objectstack-ui/SKILL.md
index eee8e3ad2bf..3fb5925c874 100644
--- a/skills/objectstack-ui/SKILL.md
+++ b/skills/objectstack-ui/SKILL.md
@@ -264,18 +264,17 @@ os validate     # CEL predicates (record.<field>) + widget bindings + schema
 # or: os build  # the same gates, plus emits dist/
 ```
 
-Two UI-specific traps it catches, both **silent at runtime** otherwise:
+Two UI-specific traps it catches, otherwise met only at runtime:
 
 - **Action / field predicate** — a bare field ref in an action `visible` /
   `disabled` or a field `visibleWhen` (`done` instead of `record.done`)
-  evaluates to `null` and hides the control on *every* record (the
-  "button never shows" trap).
+  faults on *every* record: the action hides (`visible`) or greys out
+  (`disabled`), the field shows; the console logs the fault.
 - **Dashboard widget binding** — a widget `dataset` / `dimensions` / `values`
   that doesn't resolve to a declared dataset/field renders an empty chart
   (ADR-0021).
 
-Don't report a view/action/dashboard done until `os validate` passes. In a
-scaffolded project the gate is `npm run validate`.
+In a scaffolded project the gate is `npm run validate`.
 
 ---