diff --git a/frontend/src/lib/components/copilot/chat/AIChatManager.svelte.ts b/frontend/src/lib/components/copilot/chat/AIChatManager.svelte.ts
index b8664c1221..a84bc1b31f 100644
--- a/frontend/src/lib/components/copilot/chat/AIChatManager.svelte.ts
+++ b/frontend/src/lib/components/copilot/chat/AIChatManager.svelte.ts
@@ -1793,6 +1793,13 @@ export class AIChatManager {
 		toolId: string,
 		_form: RunFormDisplay
 	): Promise<Record<string, any> | undefined> => {
+		// The tool reads the deployed schema before it asks, so a stop during that read
+		// drains the callbacks and settles the card before this runs. Installing one then
+		// would park the turn on a form the settled card no longer renders, leaving nothing
+		// able to resolve it. The controller is per-turn, so a later turn still opens.
+		if (this.abortController?.signal.aborted) {
+			return Promise.resolve(undefined)
+		}
 		return new Promise((resolve) => {
 			this.runFormCallbacks.set(toolId, resolve)
 		})
diff --git a/frontend/src/lib/components/copilot/chat/AIChatManager.test.ts b/frontend/src/lib/components/copilot/chat/AIChatManager.test.ts
index 937afc0677..26e26452e0 100644
--- a/frontend/src/lib/components/copilot/chat/AIChatManager.test.ts
+++ b/frontend/src/lib/components/copilot/chat/AIChatManager.test.ts
@@ -261,6 +261,30 @@ describe('AIChatManager run form', () => {
 		expect(manager.displayMessages[0].isLoading).toBe(true)
 	})
 
+	// The tool reads the deployed schema before it asks for arguments. A stop during that
+	// read drains the callbacks and settles the card, so a waiter installed afterwards was
+	// one no rendered form could resolve: the turn stayed loading until a second stop.
+	it('installs no run-form waiter once the turn is stopped', async () => {
+		const manager = new AIChatManager()
+		// The turn the tool is running under; cancel aborts it.
+		manager.abortController = new AbortController()
+		manager.displayMessages = [
+			{
+				role: 'tool',
+				tool_call_id: 'call_late',
+				content: 'Executing...',
+				isLoading: true
+			}
+		]
+
+		manager.cancel()
+
+		await expect(
+			manager.requestRunArgs('call_late', { path: 'f/a/b', schema: {}, args: {} })
+		).resolves.toBeUndefined()
+		expect(manager.isRunFormPending('call_late')).toBe(false)
+	})
+
 	// Stop ends the turn, not the job: the deployed script is already running with all
 	// its side effects, so the transcript must not record it as cancelled.
 	it('does not mark a started run cancelled when the turn is stopped', () => {
diff --git a/frontend/src/lib/components/job_args.test.ts b/frontend/src/lib/components/job_args.test.ts
index e96eaf4e8d..f05cde7c3d 100644
--- a/frontend/src/lib/components/job_args.test.ts
+++ b/frontend/src/lib/components/job_args.test.ts
@@ -228,6 +228,37 @@ describe('conformArgsToSchema', () => {
 		})
 	})
 
+	// A number input bound to a string renders blank and `validateInput` range-checks only
+	// an actual number, so the field passed as filled: the user approved an empty box and
+	// the job received the string.
+	it('drops a primitive that contradicts its declared scalar type', () => {
+		const schema = {
+			properties: {
+				count: { type: 'number' },
+				retries: { type: 'integer' },
+				name: { type: 'string' },
+				dry_run: { type: 'boolean' }
+			}
+		}
+		expect(
+			conformArgsToSchema(
+				{ count: 'not-a-number', retries: '3', name: 'ada', dry_run: 'false' },
+				schema
+			)
+		).toMatchObject({
+			args: { name: 'ada' },
+			dropped: { undeclared: [], unshowable: ['count', 'retries', 'dry_run'] }
+		})
+		// A dyn-select slot is `type: 'object'` holding whatever the helper returns, so
+		// only a declared scalar type constrains a primitive.
+		expect(
+			conformArgsToSchema(
+				{ tenant: 'alpha' },
+				{ properties: { tenant: { type: 'object', format: 'dynselect-list_tenants' } } }
+			)
+		).toMatchObject({ args: { tenant: 'alpha' }, dropped: { unshowable: [] } })
+	})
+
 	// A list element is bound to a widget the same way a top-level argument is, so an
 	// object in a scalar slot renders as [object Object] and the run carries it verbatim.
 	it('filters array elements whose schema declares no properties', () => {
diff --git a/frontend/src/lib/components/job_args.ts b/frontend/src/lib/components/job_args.ts
index bde36db3ff..6b8beeb07e 100644
--- a/frontend/src/lib/components/job_args.ts
+++ b/frontend/src/lib/components/job_args.ts
@@ -118,6 +118,15 @@ const declaresDynMultiselect = (prop: any) =>
 const declaresProperties = (prop: any) =>
 	prop?.properties != null && Object.keys(prop.properties).length > 0
 
+/**
+ * Whether a primitive fits a declared scalar type. Each scalar widget binds one JS type and
+ * shows nothing else: a string in a number input renders blank, and `ArgInput.validateInput`
+ * range-checks only an actual number, so the field passes as filled. The user would approve
+ * an empty box over a value only the job ever sees.
+ */
+const fitsScalarType = (value: any, type: string): boolean =>
+	type === 'integer' ? typeof value === 'number' : typeof value === type
+
 /**
  * Whether `prop` declares a slot the form can show `value` in. A value that fits nowhere
  * is one the user would approve unseen: it matches no level below, so every filter falls
@@ -127,7 +136,8 @@ const declaresProperties = (prop: any) =>
 function fitsDeclaredShape(value: any, prop: any): boolean {
 	if (value == null) return true
 	if (declaresDynMultiselect(prop)) return Array.isArray(value)
-	if (typeof value !== 'object') return true
+	if (typeof value !== 'object')
+		return !SCALAR_TYPES.has(prop?.type) || fitsScalarType(value, prop.type)
 	if (SCALAR_TYPES.has(prop?.type)) return false
 	const isArray = Array.isArray(value)
 	// Declared nested structure, never the declared `type`: a dyn-multiselect argument is