diff --git a/hub/src/agent/roleTools.ts b/hub/src/agent/roleTools.ts
index 969ac1e..9d5bc9f 100644
--- a/hub/src/agent/roleTools.ts
+++ b/hub/src/agent/roleTools.ts
@@ -77,8 +77,11 @@ const SUPPORTED_ROLE_TOOLS = new Set([
   ...Object.keys(ROLE_TOOL_TO_CPH_HUB_MCP_TOOLS),
 ]);
 
-export function claudeSdkToolConfigForRole(roleTools: readonly string[] | undefined): ClaudeSdkToolConfig {
-  if (roleTools === undefined) {
+export function claudeSdkToolConfigForRole(
+  roleTools: readonly string[] | null | undefined,
+): ClaudeSdkToolConfig {
+  // DB/runtime "unrestricted" is JSON null; treat the same as undefined.
+  if (roleTools === undefined || roleTools === null) {
     const mcpTools = CPH_HUB_MCP_TOOL_IDS.map(claudeMcpToolName);
     return {
       tools: [...DEFAULT_CLAUDE_BUILT_IN_TOOLS],
@@ -103,8 +106,10 @@ export function claudeSdkToolConfigForRole(roleTools: readonly string[] | undefi
   return { tools: builtIns, allowedTools };
 }
 
-export function cphHubMcpToolsForRole(roleTools: readonly string[] | undefined): readonly CphHubMcpToolId[] {
-  if (roleTools === undefined) return [...CPH_HUB_MCP_TOOL_IDS];
+export function cphHubMcpToolsForRole(
+  roleTools: readonly string[] | null | undefined,
+): readonly CphHubMcpToolId[] {
+  if (roleTools === undefined || roleTools === null) return [...CPH_HUB_MCP_TOOL_IDS];
 
   const tools: CphHubMcpToolId[] = [];
   for (const roleTool of roleTools) {
@@ -116,8 +121,11 @@ export function cphHubMcpToolsForRole(roleTools: readonly string[] | undefined):
   return tools;
 }
 
-export function roleToolsAllow(roleTools: readonly string[] | undefined, roleTool: string): boolean {
-  if (roleTools === undefined) return true;
+export function roleToolsAllow(
+  roleTools: readonly string[] | null | undefined,
+  roleTool: string,
+): boolean {
+  if (roleTools === undefined || roleTools === null) return true;
   for (const configured of roleTools) {
     assertSupportedRoleTool(configured);
     if (configured === roleTool) return true;
diff --git a/hub/src/agent/runner.ts b/hub/src/agent/runner.ts
index cdc23b1..ad4beb3 100644
--- a/hub/src/agent/runner.ts
+++ b/hub/src/agent/runner.ts
@@ -140,7 +140,10 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
   let cleanupSecurity = async (): Promise<void> => {};
   try {
     await persistAgentMessage(req, "user", req.prompt);
-    const toolConfig = claudeSdkToolConfigForRole(req.tools);
+    // Role tools JSON null means unrestricted (omit), not "deny all".
+    const roleToolIds = req.tools === null ? undefined : req.tools;
+    const unrestricted = roleToolIds === undefined;
+    const toolConfig = claudeSdkToolConfigForRole(roleToolIds);
     const workspaceRoot = req.project.workspaceRoot?.trim();
     if (workspaceRoot === undefined || workspaceRoot === "") {
       throw new Error("Agent run requires the configured workspace root");
@@ -154,20 +157,25 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
     });
     cleanupSecurity = security.cleanup;
     const hasSkills = security.skillIds.length > 0;
-
     type QueryOptions = NonNullable<Parameters<typeof query>[0]["options"]>;
+    // When unrestricted, pass the SDK default toolset (`--tools default`) instead of
+    // an explicit subset. Native claude uses that path to register bundled tools like
+    // TodoWrite; listing names alone can omit them from the model's function list.
+    // allowedTools still carries explicit MCP names + TodoWrite for permission.
+    const skillExtras = hasSkills ? (["Skill"] as const) : ([] as const);
+    const toolsOption: QueryOptions["tools"] = unrestricted
+      ? { type: "preset", preset: "claude_code" }
+      : uniqueTools([...toolConfig.tools, "TodoWrite", ...skillExtras]);
+    const allowedToolsOption = uniqueTools([
+      ...toolConfig.allowedTools,
+      "TodoWrite",
+      ...skillExtras,
+    ]);
+
     const options: QueryOptions = {
       cwd: security.cwd,
-      // `skills` controls discovery/allowlisting, but an explicit `tools`
-      // list still has to expose the Skill dispatcher itself.
-      // TodoWrite is always available so multi-step runs can surface a live checklist
-      // on the Feishu card (Manus-style progress), even when a role whitelists tools.
-      tools: uniqueTools([
-        ...toolConfig.tools,
-        "TodoWrite",
-        ...(hasSkills ? ["Skill"] : []),
-      ]),
-      allowedTools: uniqueTools([...toolConfig.allowedTools, "TodoWrite"]),
+      tools: toolsOption,
+      allowedTools: allowedToolsOption,
       maxTurns: cap,
       includePartialMessages: true,
       // ADR-0018: bypass interactive prompts (headless server); the sandbox
diff --git a/hub/test/unit/runner.test.ts b/hub/test/unit/runner.test.ts
index 24e8394..e0cbd08 100644
--- a/hub/test/unit/runner.test.ts
+++ b/hub/test/unit/runner.test.ts
@@ -115,7 +115,7 @@ describe("runAgent", () => {
         settingSources: [],
         settings: { disableBundledSkills: true, todoFeatureEnabled: true },
         skills: [],
-        tools: expect.arrayContaining(["TodoWrite"]),
+        tools: { type: "preset", preset: "claude_code" },
         allowedTools: expect.arrayContaining(["TodoWrite"]),
         strictMcpConfig: true,
         sandbox: expect.objectContaining({