diff --git a/skills/objectstack-platform/SKILL.md b/skills/objectstack-platform/SKILL.md
index 380e749396..06f724c755 100644
--- a/skills/objectstack-platform/SKILL.md
+++ b/skills/objectstack-platform/SKILL.md
@@ -186,8 +186,29 @@ holds a collection of one metadata kind — `manifest`, `objects`,
 There is deliberately **no** top-level `workflows` or `approvals` collection:
 an approval is authored as a flow with Approval nodes (ADR-0019), and record
 state machines are a `state_machine` validation rule on each object
-(ADR-0020). Unknown keys are **silently stripped** by strict parsing — a
-phantom key like `roles:` or `policies:` is a no-op, not an error.
+(ADR-0020). A phantom key like `roles:` or `policies:` is **not** a silent
+no-op — the top level refuses it and the stack fails to load:
+
+```
+defineStack validation failed (1 issue):
+
+  ✗ (root): Unrecognized key(s) on this stack definition: `policies`. …
+```
+
+Undeclared keys are handled per surface, and the two postures are worth
+keeping straight:
+
+- **Refused** — `defineStack()`'s top level, each `objects[]` entry
+  (`ObjectSchema`), and each field (`FieldSchema`). The parse throws, naming
+  the surface and the offending key. TypeScript rejects the literal earlier
+  still, with `TS2353: Object literal may only specify known properties`.
+- **Warned, then dropped** — the authoring surfaces whose shapes have not
+  been closed yet (`connectors` is one). `defineStack()` prints the warning
+  before the parse, and the value does not survive it:
+  `defineStack: connectors.stripe.bogusKey: 'bogusKey' is not a declared connector key, so its value is dropped at load.`
+  Treat these as errors-in-waiting — closing the remaining shapes is a
+  scheduled migration, so a key that only warns today is expected to be
+  refused later.
 
 For the exact Zod shape — including which keys are optional and what types
 the collection items take — read
@@ -1042,7 +1063,7 @@ const metrics = kernel.getPluginMetrics();
 ## Feature Flags
 
 Feature flags are **not a spec/metadata concept**. There is no `featureFlags:` /
-`features:` key on `defineStack` (strict parsing silently strips unknown keys), and the
+`features:` key on `defineStack` (writing one is refused at load, not stripped), and the
 former `FeatureFlagSchema` (`@objectstack/spec/kernel`) was removed — it had zero runtime
 consumers, and its only protocol home (the static `ObjectStackCapabilities.system.features`
 descriptor) was itself dead: no endpoint ever served it. Runtime capability discovery is
diff --git a/skills/objectstack-platform/rules/bootstrap-patterns.md b/skills/objectstack-platform/rules/bootstrap-patterns.md
index d5e10b6c8a..42b027f203 100644
--- a/skills/objectstack-platform/rules/bootstrap-patterns.md
+++ b/skills/objectstack-platform/rules/bootstrap-patterns.md
@@ -4,9 +4,27 @@ Guide for bootstrapping ObjectStack projects with defineStack().
 
 ## Basic Stack Configuration
 
-There is **no `driver:` key** on `defineStack()` — unknown keys are silently
-stripped by strict parsing, so a `driver:` entry is a no-op. Drivers are
-plugins: wrap them in `DriverPlugin` and put them in `plugins:`.
+There is **no `driver:` key** on `defineStack()`. Drivers are plugins: wrap
+them in `DriverPlugin` and put them in `plugins:`.
+
+A `driver:` entry is **not** a harmless no-op. The top level of a stack
+definition rejects undeclared keys, so the stack does not load:
+
+```
+defineStack validation failed (1 issue):
+
+  ✗ (root): Unrecognized key(s) on this stack definition: `driver`. …
+    The declared keys are enumerated by `ObjectStackDefinitionSchema`
+    (@objectstack/spec, stack.zod.ts) and in the stack-definition
+    reference docs.
+```
+
+TypeScript refuses it earlier still, at compile time:
+
+```
+error TS2353: Object literal may only specify known properties,
+and 'driver' does not exist in type 'ObjectStackDefinitionInput'.
+```
 
 The `manifest` requires `id`, `version`, `type`, and `name`
 (`ManifestSchema` is strict — a missing required field throws at
@@ -66,12 +84,12 @@ There are no `@objectstack/adapter-*` packages.
 
 ## Incorrect vs Correct
 
-### ❌ Incorrect — `driver:` Key (Silently Stripped)
+### ❌ Incorrect — `driver:` Key (Rejected at Load)
 
 ```typescript
 export default defineStack({
   manifest: { id: 'com.example.app', version: '1.0.0', type: 'app', name: 'App' },
-  driver: new DriverPlugin(new InMemoryDriver()),  // ❌ Not a defineStack key — no-op
+  driver: new DriverPlugin(new InMemoryDriver()),  // ❌ Not a defineStack key — defineStack throws
   objects: [/* ... */],
 });
 ```