diff --git a/src/perspicacite/mcp/server.py b/src/perspicacite/mcp/server.py
index 87b1569..b5768fe 100644
--- a/src/perspicacite/mcp/server.py
+++ b/src/perspicacite/mcp/server.py
@@ -5304,6 +5304,8 @@ async def zotero_get_attachment_bytes(
     if not eff_library_id:
         return {"error": "ZOTERO_NOT_CONFIGURED", "message": "library_id required"}
 
+    import httpx
+
     from perspicacite.integrations.zotero import ZoteroClient
 
     client = ZoteroClient(
diff --git a/src/perspicacite/web/routers/kb.py b/src/perspicacite/web/routers/kb.py
index aef96f8..6c63aed 100644
--- a/src/perspicacite/web/routers/kb.py
+++ b/src/perspicacite/web/routers/kb.py
@@ -879,7 +879,7 @@ async def kb_export(name: str, format: str = "obsidian-vault"):
                 "abstract": m.get("abstract"),
             })
     except Exception as exc:
-        logger.warning("kb_export_paper_enum_failed", kb=name, error=str(exc))
+        logger.warning("kb_export_paper_enum_failed kb=%s: %s", name, exc)
         papers = []
 
     # Conversations linked to this KB
@@ -899,7 +899,7 @@ async def kb_export(name: str, format: str = "obsidian-vault"):
             c_dict["messages"] = msgs
             conv_dicts.append(c_dict)
     except Exception as exc:
-        logger.warning("kb_export_conv_enum_failed", kb=name, error=str(exc))
+        logger.warning("kb_export_conv_enum_failed kb=%s: %s", name, exc)
         conv_dicts = []
 
     kb_dict = kb.model_dump()
diff --git a/src/perspicacite/web/state.py b/src/perspicacite/web/state.py
index a002c2c..0f694ed 100644
--- a/src/perspicacite/web/state.py
+++ b/src/perspicacite/web/state.py
@@ -166,7 +166,7 @@ async def initialize(self):
             tool_registry.register(WebSearchTool(app_state=self))
             logger.info("Tool registry initialized (web_search registered, LOTUS deactivated)")
         except Exception as exc:  # pragma: no cover - best-effort
-            logger.warning("web_search_tool_register_failed", error=str(exc))
+            logger.warning("web_search_tool_register_failed: %s", exc)
             logger.info("Tool registry initialized (LOTUS deactivated)")
 
         # Create LLM adapter for agentic components
diff --git a/tests/unit/test_logger_call_conventions.py b/tests/unit/test_logger_call_conventions.py
new file mode 100644
index 0000000..b6875de
--- /dev/null
+++ b/tests/unit/test_logger_call_conventions.py
@@ -0,0 +1,68 @@
+"""Guard: a stdlib logger must never be called with structlog-style keyword args.
+
+Most modules bind `logger` with `perspicacite.logging.get_logger`, a structlog
+logger where `logger.warning("event", kb=name)` is the intended API. A handful
+bind it with `logging.getLogger`, where the same call raises
+`TypeError: _log() got an unexpected keyword argument 'kb'`.
+
+Every offending call found so far sat inside an `except` block whose job was to
+degrade gracefully, so the handler replaced a recoverable failure with a crash.
+"""
+
+import ast
+from pathlib import Path
+
+SOURCE_ROOT = Path(__file__).resolve().parents[2] / "src"
+
+# Keyword arguments logging.Logger.debug/info/warning/... actually accepts.
+STDLIB_LOG_KWARGS = frozenset({"exc_info", "stack_info", "stacklevel", "extra"})
+LOG_METHODS = frozenset({"debug", "info", "warning", "error", "exception", "critical", "log"})
+
+
+def _logger_names_by_binding(tree: ast.Module) -> tuple[set[str], set[str]]:
+    """Return the names bound to a stdlib logger and to a structlog logger."""
+    stdlib: set[str] = set()
+    structlog: set[str] = set()
+    for node in ast.walk(tree):
+        if not isinstance(node, ast.Assign) or not isinstance(node.value, ast.Call):
+            continue
+        targets = {t.id for t in node.targets if isinstance(t, ast.Name)}
+        func = node.value.func
+        if isinstance(func, ast.Attribute) and func.attr == "getLogger":
+            stdlib |= targets
+        elif isinstance(func, ast.Name) and func.id == "get_logger":
+            structlog |= targets
+    return stdlib, structlog
+
+
+def _rejected_keyword_calls(tree: ast.Module, stdlib_names: set[str]) -> list[tuple[int, str]]:
+    """Find stdlib-logger calls passing a keyword the stdlib will reject."""
+    offenders = []
+    for node in ast.walk(tree):
+        if not isinstance(node, ast.Call) or not isinstance(node.func, ast.Attribute):
+            continue
+        target = node.func.value
+        if node.func.attr not in LOG_METHODS or not isinstance(target, ast.Name):
+            continue
+        if target.id not in stdlib_names:
+            continue
+        rejected = [kw.arg for kw in node.keywords if kw.arg not in STDLIB_LOG_KWARGS]
+        if rejected:
+            offenders.append((node.lineno, ", ".join(sorted(rejected))))
+    return offenders
+
+
+def test_no_stdlib_logger_is_called_with_structlog_keywords():
+    """A rejected keyword turns any log line into a TypeError at call time."""
+    failures = []
+    for path in sorted(SOURCE_ROOT.rglob("*.py")):
+        tree = ast.parse(path.read_text(encoding="utf-8"))
+        stdlib_names, structlog_names = _logger_names_by_binding(tree)
+        # A name rebound to get_logger later is a structlog logger; leave it alone.
+        for line, keywords in _rejected_keyword_calls(tree, stdlib_names - structlog_names):
+            failures.append(f"{path.relative_to(SOURCE_ROOT.parent)}:{line} passes {keywords}")
+
+    assert not failures, (
+        "stdlib logging.Logger rejects these keyword arguments, so each call raises "
+        "TypeError when it runs:\n  " + "\n  ".join(failures)
+    )