diff --git a/swh/scanner/exceptions.py b/swh/scanner/exceptions.py
--- a/swh/scanner/exceptions.py
+++ b/swh/scanner/exceptions.py
@@ -6,4 +6,16 @@
 
 class APIError(Exception):
     def __str__(self):
-        return 'API Error: "%s"' % self.args
+        return '"%s"' % self.args
+
+
+status_code_msg = {
+    404: 'Resource not found',
+    413: 'Payload Too Large',
+    429: 'Too many request',
+}
+
+
+def error_response(status_code: int, api_url: str):
+    error_msg = f'{status_code} {status_code_msg[status_code]}: \'{api_url}\''
+    raise APIError(error_msg)
diff --git a/swh/scanner/scanner.py b/swh/scanner/scanner.py
--- a/swh/scanner/scanner.py
+++ b/swh/scanner/scanner.py
@@ -10,7 +10,7 @@
 from typing import List, Dict, Tuple, Iterator
 from pathlib import PosixPath
 
-from .exceptions import APIError
+from .exceptions import error_response
 from .model import Tree
 
 from swh.model.cli import pid_of_file, pid_of_dir
@@ -49,9 +49,7 @@
     async def make_request(pids):
         async with session.post(endpoint, json=pids) as resp:
             if resp.status != 200:
-                error_message = '%s with given values %s' % (
-                    resp.text, str(pids))
-                raise APIError(error_message)
+                error_response(resp.status, endpoint)
 
             return await resp.json()