diff --git a/src/fi/alk/providers/agent.py b/src/fi/alk/providers/agent.py
index 18cf6dbdd..44ecb7657 100644
--- a/src/fi/alk/providers/agent.py
+++ b/src/fi/alk/providers/agent.py
@@ -233,6 +233,15 @@ def _authored_tool(
 
 
 def _redact(value: Any, key: str = "") -> Any:
+    refused: list[str] = []
+    redacted = _redact_in(value, key, refused)
+    if refused:
+        # Once per document, not per string: a crafted contract can hold half a million of them.
+        logger.warning("a URL was redacted whole: class=%s", refused[0])
+    return redacted
+
+
+def _redact_in(value: Any, key: str, refused: list[str]) -> Any:
     lowered = key.lower()
     if any(marker in lowered for marker in _REDACTION_MARKERS):
         return _REDACTED
@@ -242,18 +251,19 @@ def _redact(value: Any, key: str = "") -> Any:
         return _REDACTED
     if isinstance(value, Mapping):
         return {
-            str(item_key): _redact(item, str(item_key))
+            str(item_key): _redact_in(item, str(item_key), refused)
             for item_key, item in value.items()
         }
     if isinstance(value, list):
-        return [_redact(item, key) for item in value]
+        return [_redact_in(item, key, refused) for item in value]
     if isinstance(value, str) and "://" in value:
         try:
             parsed = urlsplit(value)
-        except ValueError as refused:
+        except ValueError as error:
             # A netloc urlsplit refuses may still hold credentials, so none of it is kept, and
             # only the error's class is logged: its text repeats the netloc.
-            logger.warning("a URL was redacted whole: class=%s", type(refused).__name__)
+            if not refused:
+                refused.append(type(error).__name__)
             return _REDACTED
         if parsed.scheme and parsed.netloc:
             hostname = parsed.hostname or ""
diff --git a/tests/harness/test_agent_reading.py b/tests/harness/test_agent_reading.py
index 6cb89b154..a3ef8c60b 100644
--- a/tests/harness/test_agent_reading.py
+++ b/tests/harness/test_agent_reading.py
@@ -861,6 +861,11 @@ def test_the_longest_stop_leaves_room_for_the_document_inside_the_margin():
     )
     assert bounds == (10.0, 60.0, 20.0)
     assert sum(bounds) == 90.0
+    # And the reading the platform runs waits after the interrupt for exactly that bound.
+    assert agent_reading.READ_AGENT.work.func is agent_reading._read
+    assert agent_reading.READ_AGENT.work.keywords == {
+        "interrupt_wait": agent_reading._INTERRUPT_WAIT_SECONDS
+    }
     # Then the saved contract's document, whose framework scan can take over a minute on a
     # crafted repository: at least 150 s of the margin stays for it.
     assert sum(bounds) + 150.0 < agent_reading._HARD_LIMIT_MARGIN_SECONDS
diff --git a/tests/providers/test_providers_agent_build.py b/tests/providers/test_providers_agent_build.py
index dbc5a92b6..393c6f7eb 100644
--- a/tests/providers/test_providers_agent_build.py
+++ b/tests/providers/test_providers_agent_build.py
@@ -1,11 +1,12 @@
 from __future__ import annotations
 
+import logging
 from typing import Any
 
 import pytest
 
 from fi.alk.harness.provider_import import _safe_profile_value
-from fi.alk.providers.agent import _redact
+from fi.alk.providers.agent import _redact, build_authored_agent
 
 PLAIN_DOCUMENTS: list[Any] = [
     {"name": "Support line", "voice": {"voiceId": "marissa", "speed": 1.0}},
@@ -55,3 +56,28 @@ def test_added_markers_headers_and_parameters() -> None:
         "headers": "[redacted]",
         "url": "https://example.com/x",
     }
+
+
+def test_many_refused_urls_in_one_document_log_one_line(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    # A full-width number sign NFKC-normalises to "#", and "[" opens an IPv6 host that never
+    # closes: urlsplit refuses both.
+    leaky = "https://admin:hunter2\uff03x@db.example/"
+    refused = [leaky, *(["a://["] * 1000)]
+    document = {
+        "agent": "support",
+        "modality": "chat",
+        "system_prompt_excerpt": leaky,
+        "tools": [{"name": "add", "args": ["k"], "arg_values": {"k": refused}}],
+    }
+
+    with caplog.at_level(logging.DEBUG, logger="fi.alk.providers.agent"):
+        agent = build_authored_agent(document)
+
+    assert agent["behaviour"][0]["instructions"] == "[redacted]"
+    assert agent["tools"][0]["parameters"]["properties"]["k"]["enum"] == ["[redacted]"] * 1001
+    [logged] = [record for record in caplog.records if record.name == "fi.alk.providers.agent"]
+    assert logged.getMessage() == "a URL was redacted whole: class=ValueError"
+    assert logged.exc_info is None
+    assert "hunter2" not in caplog.text