diff --git a/packages/tools/src/ai-sdk.ts b/packages/tools/src/ai-sdk.ts
index 97d6a36bf..fbc443722 100644
--- a/packages/tools/src/ai-sdk.ts
+++ b/packages/tools/src/ai-sdk.ts
@@ -247,6 +247,15 @@ export const documentDeleteTool = (
 		}),
 		execute: async ({ documentId, containerTag }) => {
 			try {
+				// A model-supplied tag may only select one of the tags the developer
+				// configured. Accepting an arbitrary value would let the model delete
+				// documents outside the configured scope.
+				if (containerTag && !containerTags.includes(containerTag)) {
+					throw new Error(
+						`Container tag "${containerTag}" is outside the configured scope.`,
+					)
+				}
+
 				const scopeTags: [string, ...string[]] = containerTag
 					? [containerTag]
 					: containerTags
diff --git a/packages/tools/src/document-delete-scope.test.ts b/packages/tools/src/document-delete-scope.test.ts
new file mode 100644
index 000000000..25f10932f
--- /dev/null
+++ b/packages/tools/src/document-delete-scope.test.ts
@@ -0,0 +1,141 @@
+import { beforeEach, describe, expect, it, vi } from "vitest"
+
+// Mock the Supermemory SDK (same pattern as tool-operations.test.ts) so tool
+// executions can be verified deterministically without network access.
+const documentsDeleteBulk = vi.fn()
+const documentsGet = vi.fn()
+const documentsList = vi.fn()
+
+vi.mock("supermemory", () => {
+	return {
+		default: class MockSupermemory {
+			documents = {
+				deleteBulk: documentsDeleteBulk,
+				get: documentsGet,
+				list: documentsList,
+			}
+		},
+	}
+})
+
+import * as aiSdk from "./ai-sdk"
+import * as openAi from "./openai/tools"
+
+const API_KEY = "sm_test_key"
+
+type ToolExecutionResult = { success: boolean; error?: string }
+type ToolWithExecute = {
+	execute: (args: Record<string, unknown>) => Promise<ToolExecutionResult>
+}
+
+function executeTool(
+	tool: unknown,
+	args: Record<string, unknown>,
+): Promise<ToolExecutionResult> {
+	return (tool as ToolWithExecute).execute(args)
+}
+
+beforeEach(() => {
+	documentsDeleteBulk.mockReset().mockResolvedValue({
+		success: true,
+		deletedCount: 1,
+		errors: [],
+	})
+	documentsGet.mockReset()
+	documentsList.mockReset().mockResolvedValue({
+		memories: [],
+		pagination: { currentPage: 1, totalItems: 0, totalPages: 0 },
+	})
+})
+
+describe("documentDelete configured container scope", () => {
+	it("ai-sdk refuses a model-supplied tag outside the configured scope", async () => {
+		documentsGet.mockResolvedValue({
+			id: "doc_in_tenant_b",
+			customId: "doc_in_tenant_b",
+			containerTags: ["tenant-b"],
+		})
+
+		const result = await executeTool(
+			aiSdk.documentDeleteTool(API_KEY, { containerTags: ["tenant-a"] }),
+			{ documentId: "doc_in_tenant_b", containerTag: "tenant-b" },
+		)
+
+		expect(result.success).toBe(false)
+		expect(result.error).toContain("outside the configured scope")
+		expect(documentsGet).not.toHaveBeenCalled()
+		expect(documentsList).not.toHaveBeenCalled()
+		expect(documentsDeleteBulk).not.toHaveBeenCalled()
+	})
+
+	it("openai refuses a model-supplied tag outside the configured scope", async () => {
+		documentsGet.mockResolvedValue({
+			id: "doc_in_tenant_b",
+			customId: "doc_in_tenant_b",
+			containerTags: ["tenant-b"],
+		})
+
+		const documentDelete = openAi.createDocumentDeleteFunction(API_KEY, {
+			containerTags: ["tenant-a"],
+		})
+		const result = await documentDelete({
+			documentId: "doc_in_tenant_b",
+			containerTag: "tenant-b",
+		})
+
+		expect(result.success).toBe(false)
+		expect(result.error).toContain("outside the configured scope")
+		expect(documentsGet).not.toHaveBeenCalled()
+		expect(documentsList).not.toHaveBeenCalled()
+		expect(documentsDeleteBulk).not.toHaveBeenCalled()
+	})
+
+	it("rejects tags outside an implicit project scope", async () => {
+		const result = await executeTool(
+			aiSdk.documentDeleteTool(API_KEY, { projectId: "alpha" }),
+			{ documentId: "doc_1", containerTag: "tenant-b" },
+		)
+
+		expect(result.success).toBe(false)
+		expect(result.error).toContain("outside the configured scope")
+		expect(documentsDeleteBulk).not.toHaveBeenCalled()
+	})
+
+	it("allows selecting another explicitly configured tag", async () => {
+		documentsGet.mockResolvedValue({
+			id: "doc_in_tenant_b",
+			customId: "doc_in_tenant_b",
+			containerTags: ["tenant-b"],
+		})
+
+		const result = await executeTool(
+			aiSdk.documentDeleteTool(API_KEY, {
+				containerTags: ["tenant-a", "tenant-b"],
+			}),
+			{ documentId: "doc_in_tenant_b", containerTag: "tenant-b" },
+		)
+
+		expect(result.success).toBe(true)
+		expect(documentsDeleteBulk).toHaveBeenCalledWith({
+			ids: ["doc_in_tenant_b"],
+		})
+	})
+
+	it("keeps the configured union when no tag is supplied", async () => {
+		documentsGet.mockResolvedValue({
+			id: "doc_in_tenant_a",
+			customId: "doc_in_tenant_a",
+			containerTags: ["tenant-a"],
+		})
+
+		const result = await executeTool(
+			aiSdk.documentDeleteTool(API_KEY, { containerTags: ["tenant-a"] }),
+			{ documentId: "doc_in_tenant_a" },
+		)
+
+		expect(result.success).toBe(true)
+		expect(documentsDeleteBulk).toHaveBeenCalledWith({
+			ids: ["doc_in_tenant_a"],
+		})
+	})
+})
diff --git a/packages/tools/src/openai/tools.ts b/packages/tools/src/openai/tools.ts
index 1be290849..8949aafbe 100644
--- a/packages/tools/src/openai/tools.ts
+++ b/packages/tools/src/openai/tools.ts
@@ -414,6 +414,15 @@ export function createDocumentDeleteFunction(
 		containerTag?: string
 	}): Promise<DocumentDeleteResult> {
 		try {
+			// A model-supplied tag may only select one of the tags the developer
+			// configured. Accepting an arbitrary value would let the model delete
+			// documents outside the configured scope.
+			if (containerTag && !containerTags.includes(containerTag)) {
+				throw new Error(
+					`Container tag "${containerTag}" is outside the configured scope.`,
+				)
+			}
+
 			const scopeTags: [string, ...string[]] = containerTag
 				? [containerTag]
 				: containerTags