diff --git a/src/core/assistant-message/__tests__/presentAssistantMessage-validation-errors.spec.ts b/src/core/assistant-message/__tests__/presentAssistantMessage-validation-errors.spec.ts
new file mode 100644
index 0000000000..af2d3f9acd
--- /dev/null
+++ b/src/core/assistant-message/__tests__/presentAssistantMessage-validation-errors.spec.ts
@@ -0,0 +1,89 @@
+// npx vitest run src/core/assistant-message/__tests__/presentAssistantMessage-validation-errors.spec.ts
+
+import { describe, it, expect, beforeEach, vi } from "vitest"
+import { presentAssistantMessage } from "../presentAssistantMessage"
+
+// Mock validateToolUse to ensure we don't depend on its behavior for this test.
+vi.mock("../../tools/validateToolUse", () => ({
+	validateToolUse: vi.fn(),
+}))
+
+vi.mock("@roo-code/telemetry", () => ({
+	TelemetryService: {
+		instance: {
+			captureToolUsage: vi.fn(),
+			captureConsecutiveMistakeError: vi.fn(),
+		},
+	},
+}))
+
+describe("presentAssistantMessage - validation/missing-param handling", () => {
+	let mockTask: any
+
+	beforeEach(() => {
+		mockTask = {
+			taskId: "test-task-id",
+			instanceId: "test-instance",
+			abort: false,
+			presentAssistantMessageLocked: false,
+			presentAssistantMessageHasPendingUpdates: false,
+			currentStreamingContentIndex: 0,
+			assistantMessageContent: [],
+			userMessageContent: [],
+			didCompleteReadingStream: true,
+			userMessageContentReady: false,
+			didRejectTool: false,
+			didAlreadyUseTool: false,
+			diffEnabled: false,
+			consecutiveMistakeCount: 0,
+			didToolFailInCurrentTurn: false,
+			clineMessages: [],
+			api: {
+				getModel: () => ({ id: "test-model", info: {} }),
+			},
+			browserSession: {
+				closeBrowser: vi.fn().mockResolvedValue(undefined),
+			},
+			recordToolUsage: vi.fn(),
+			recordToolError: vi.fn(),
+			toolRepetitionDetector: {
+				check: vi.fn().mockReturnValue({ allowExecution: true }),
+			},
+			providerRef: {
+				deref: () => ({
+					getState: vi.fn().mockResolvedValue({
+						mode: "orchestrator",
+						customModes: [],
+					}),
+				}),
+			},
+			say: vi.fn().mockResolvedValue(undefined),
+			ask: vi.fn().mockResolvedValue({ response: "yesButtonClicked" }),
+			sayAndCreateMissingParamError: vi.fn().mockResolvedValue("missing param"),
+		}
+	})
+
+	it("treats missing codebase_search.path as missing param when read fileRegex is present (native protocol)", async () => {
+		const toolCallId = "tool_call_missing_path"
+		mockTask.assistantMessageContent = [
+			{
+				type: "tool_use",
+				id: toolCallId,
+				name: "codebase_search",
+				params: { query: "x" },
+				partial: false,
+			},
+		]
+
+		// Make orchestrator mode config discoverable via shared/modes.getModeBySlug() (built-in DEFAULT_MODES)
+		await presentAssistantMessage(mockTask)
+
+		expect(mockTask.sayAndCreateMissingParamError).toHaveBeenCalledWith("codebase_search", "path")
+		const toolResult = mockTask.userMessageContent.find(
+			(item: any) => item.type === "tool_result" && item.tool_use_id === toolCallId,
+		)
+		expect(toolResult).toBeDefined()
+		expect(toolResult.is_error).toBe(true)
+		expect(mockTask.userMessageContentReady).toBe(true)
+	})
+})
diff --git a/src/core/assistant-message/presentAssistantMessage.ts b/src/core/assistant-message/presentAssistantMessage.ts
index 0367e71ce3..ae4d79971e 100644
--- a/src/core/assistant-message/presentAssistantMessage.ts
+++ b/src/core/assistant-message/presentAssistantMessage.ts
@@ -356,6 +356,10 @@ export async function presentAssistantMessage(cline: Task) {
 			// Fetch state early so it's available for toolDescription and validation
 			const state = await cline.providerRef.deref()?.getState()
 			const { mode, customModes, experiments: stateExperiments } = state ?? {}
+			const activeModeConfig = getModeBySlug(mode ?? defaultModeSlug, customModes)
+			const readGroupEntry = activeModeConfig?.groups.find((g) => (Array.isArray(g) ? g[0] : g) === "read")
+			const readGroupOptions = Array.isArray(readGroupEntry) ? readGroupEntry[1] : undefined
+			const readFileRegex = readGroupOptions?.fileRegex
 
 			const toolDescription = (): string => {
 				switch (block.name) {
@@ -720,6 +724,34 @@ export async function presentAssistantMessage(cline: Task) {
 					? { ...block.params, ...block.nativeArgs }
 					: block.params
 
+				// In modes that restrict read access via fileRegex (e.g., Orchestrator),
+				// codebase_search must NOT run with a missing/empty path because that implies
+				// an unrestricted workspace search.
+				//
+				// Instead of throwing a FileRestrictionError (which is confusing here), treat
+				// it like a missing required parameter so the model can retry with a safe path.
+				if (block.name === "codebase_search" && typeof readFileRegex === "string" && readFileRegex.length > 0) {
+					const rawPath = (toolParamsForValidation as { path?: unknown }).path
+					if (typeof rawPath !== "string" || rawPath.trim().length === 0) {
+						cline.consecutiveMistakeCount++
+						cline.didToolFailInCurrentTurn = true
+						const missingParamError = await cline.sayAndCreateMissingParamError("codebase_search", "path")
+
+						if (toolProtocol === TOOL_PROTOCOL.NATIVE && toolCallId) {
+							cline.userMessageContent.push({
+								type: "tool_result",
+								tool_use_id: toolCallId,
+								content:
+									typeof missingParamError === "string" ? missingParamError : "(missing parameter)",
+								is_error: true,
+							} as Anthropic.ToolResultBlockParam)
+						} else {
+							pushToolResult(missingParamError)
+						}
+						break
+					}
+				}
+
 				try {
 					validateToolUse(
 						block.name as ToolName,