diff --git a/gcontacts/contacts_tools.py b/gcontacts/contacts_tools.py
index dd7143f..ab04053 100644
--- a/gcontacts/contacts_tools.py
+++ b/gcontacts/contacts_tools.py
@@ -249,10 +249,14 @@ async def list_contacts(
     """
     logger.info(f"[list_contacts] Invoked. Email: '{user_google_email}'")
 
+    if page_size < 1:
+        raise UserInputError("page_size must be >= 1")
+    page_size = min(page_size, 1000)
+
     params: Dict[str, Any] = {
         "resourceName": "people/me",
         "personFields": DEFAULT_PERSON_FIELDS,
-        "pageSize": min(page_size, 1000),
+        "pageSize": page_size,
     }
 
     if page_token:
@@ -350,6 +354,10 @@ async def search_contacts(
         f"[search_contacts] Invoked. Email: '{user_google_email}', Query: '{query}'"
     )
 
+    if page_size < 1:
+        raise UserInputError("page_size must be >= 1")
+    page_size = min(page_size, 30)
+
     # Warm up the search cache if needed
     await _warmup_search_cache(service, user_google_email)
 
@@ -358,7 +366,7 @@ async def search_contacts(
         .searchContacts(
             query=query,
             readMask=DEFAULT_PERSON_FIELDS,
-            pageSize=min(page_size, 30),
+            pageSize=page_size,
         )
         .execute
     )
@@ -561,8 +569,12 @@ async def list_contact_groups(
     """
     logger.info(f"[list_contact_groups] Invoked. Email: '{user_google_email}'")
 
+    if page_size < 1:
+        raise UserInputError("page_size must be >= 1")
+    page_size = min(page_size, 1000)
+
     params: Dict[str, Any] = {
-        "pageSize": min(page_size, 1000),
+        "pageSize": page_size,
         "groupFields": CONTACT_GROUP_FIELDS,
     }
 
@@ -628,11 +640,15 @@ async def get_contact_group(
         f"[get_contact_group] Invoked. Email: '{user_google_email}', Group: {resource_name}"
     )
 
+    if max_members < 1:
+        raise UserInputError("max_members must be >= 1")
+    max_members = min(max_members, 1000)
+
     result = await asyncio.to_thread(
         service.contactGroups()
         .get(
             resourceName=resource_name,
-            maxMembers=min(max_members, 1000),
+            maxMembers=max_members,
             groupFields=CONTACT_GROUP_FIELDS,
         )
         .execute
diff --git a/gtasks/tasks_tools.py b/gtasks/tasks_tools.py
index 7607183..28cbaab 100644
--- a/gtasks/tasks_tools.py
+++ b/gtasks/tasks_tools.py
@@ -341,7 +341,7 @@ async def manage_task_list(
     return await _clear_completed_tasks_impl(service, user_google_email, task_list_id)
 
 
-# --- Legacy task list tools (wrappers around _impl functions) ---
+# --- Task tools ---
 
 
 @server.tool()  # type: ignore
@@ -871,6 +871,12 @@ async def manage_task(
         f"[manage_task] Invoked. Email: '{user_google_email}', Action: '{action}', Task List ID: {task_list_id}"
     )
 
+    allowed_statuses = {"needsAction", "completed"}
+    if status is not None and status not in allowed_statuses:
+        raise UserInputError(
+            "invalid status: must be 'needsAction' or 'completed'"
+        )
+
     valid_actions = ("create", "update", "delete", "move")
     if action not in valid_actions:
         raise UserInputError(
@@ -878,6 +884,8 @@ async def manage_task(
         )
 
     if action == "create":
+        if status is not None:
+            raise UserInputError("'status' is only supported for the 'update' action.")
         if not title:
             raise UserInputError("'title' is required for the 'create' action.")
         return await _create_task_impl(
@@ -892,6 +900,10 @@ async def manage_task(
         )
 
     if action == "update":
+        if status is not None and status not in allowed_statuses:
+            raise UserInputError(
+                "invalid status: must be 'needsAction' or 'completed'"
+            )
         if not task_id:
             raise UserInputError("'task_id' is required for the 'update' action.")
         return await _update_task_impl(
@@ -924,6 +936,3 @@ async def manage_task(
         previous=previous,
         destination_task_list=destination_task_list,
     )
-
-
-# --- Legacy task tools (wrappers around _impl functions) ---