diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index e0565f7bd..57dded4dc 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -413,7 +413,7 @@ repos:
           - *uv_version
 
       - id: yamlfix
-        name: pyproject-fmt
+        name: yamlfix
         entry: uv run --extra=dev yamlfix
         language: python
         types_or: [yaml]
diff --git a/ci/test_custom_linters.py b/ci/test_custom_linters.py
index 3ba81680b..6988b1cac 100644
--- a/ci/test_custom_linters.py
+++ b/ci/test_custom_linters.py
@@ -1,5 +1,6 @@
 """Custom lint tests."""
 
+import ast
 from pathlib import Path
 
 import pytest
@@ -7,6 +8,61 @@
 from beartype import beartype
 
 
+def test_pre_commit_hook_identifiers_unique(
+    request: pytest.FixtureRequest,
+) -> None:
+    """Each pre-commit hook has a unique ID and display name."""
+    config_file = request.config.rootpath / ".pre-commit-config.yaml"
+    config = yaml.safe_load(stream=config_file.read_text())
+    hooks = [
+        hook
+        for repository in config["repos"]
+        for hook in repository.get("hooks", [])
+    ]
+    hook_ids = [hook["id"] for hook in hooks]
+    hook_names = [hook.get("name", hook["id"]) for hook in hooks]
+
+    assert len(hook_ids) == len(set(hook_ids)), (
+        "Pre-commit hook IDs must be unique."
+    )
+    assert len(hook_names) == len(set(hook_names)), (
+        "Pre-commit hook names must be unique."
+    )
+
+
+def test_validate_and_run_functions_are_keyword_only(
+    request: pytest.FixtureRequest,
+) -> None:
+    """Validation and runner APIs do not accept positional arguments."""
+    violations: list[str] = []
+    source_root = request.config.rootpath / "src"
+
+    for source_file in source_root.rglob("*.py"):
+        module = ast.parse(source_file.read_text())
+        for function in ast.walk(module):
+            if not isinstance(
+                function, ast.FunctionDef | ast.AsyncFunctionDef
+            ):
+                continue
+            if not function.name.startswith(("validate_", "run_")):
+                continue
+            positional_arguments = [
+                argument.arg
+                for argument in [
+                    *function.args.posonlyargs,
+                    *function.args.args,
+                ]
+                if argument.arg not in {"self", "cls"}
+            ]
+            if positional_arguments:
+                path = source_file.relative_to(request.config.rootpath)
+                violations.append(f"{path}:{function.lineno} {function.name}")
+
+    assert not violations, "Functions must be keyword-only: " + ", ".join(
+        violations
+    )
+
+
 @beartype
 def _ci_patterns(*, repository_root: Path) -> set[str]:
     """Return the CI patterns given in the CI configuration file."""
diff --git a/src/mock_vws/_query_validators/accept_header_validators.py b/src/mock_vws/_query_validators/accept_header_validators.py
index fe3e966f6..e2387f913 100644
--- a/src/mock_vws/_query_validators/accept_header_validators.py
+++ b/src/mock_vws/_query_validators/accept_header_validators.py
@@ -11,7 +11,7 @@
 
 
 @beartype
-def validate_accept_header(request_headers: Mapping[str, str]) -> None:
+def validate_accept_header(*, request_headers: Mapping[str, str]) -> None:
     """Validate the accept header.
 
     Args:
diff --git a/src/mock_vws/_query_validators/auth_validators.py b/src/mock_vws/_query_validators/auth_validators.py
index 13553efa4..ddd4310ea 100644
--- a/src/mock_vws/_query_validators/auth_validators.py
+++ b/src/mock_vws/_query_validators/auth_validators.py
@@ -88,6 +88,7 @@ def validate_client_key_exists(
 
 @beartype
 def validate_auth_header_has_signature(
+    *,
     request_headers: Mapping[str, str],
 ) -> None:
     """Validate the authorization header includes a signature.