diff --git a/tools/linter_lib/custom_check.py b/tools/linter_lib/custom_check.py
index 479f00cae9..e1c2b491f9 100644
--- a/tools/linter_lib/custom_check.py
+++ b/tools/linter_lib/custom_check.py
@@ -280,19 +280,29 @@ def build_custom_checkers(by_lang):
          'exclude': set(['tools/tests',
                          'zerver/lib/test_runner.py',
                          'zerver/tests']),
-         'description': '"type: ignore" should always end with "# type: ignore # explanation for why"'},
+         'description': '"type: ignore" should always end with "# type: ignore # explanation for why"',
+         'good_lines': ['foo = bar  # type: ignore # explanation'],
+         'bad_lines': ['foo = bar  # type: ignore']},
         {'pattern': "# type [(]",
-         'description': 'Missing : after type in type annotation'},
+         'description': 'Missing : after type in type annotation',
+         'good_lines': ['foo = 42  # type: int', '# type: (str, int) -> None'],
+         'bad_lines': ['# type (str, int) -> None']},
         {'pattern': "#type",
-         'description': 'Missing whitespace after "#" in type annotation'},
+         'description': 'Missing whitespace after "#" in type annotation',
+         'good_lines': ['foo = 42  # type: int'],
+         'bad_lines': ['foo = 42  #type: int']},
         {'pattern': r'\b(if|else|while)[(]',
          'description': 'Put a space between statements like if, else, etc. and (.',
          'good_lines': ['if (1 == 2):', 'while (foo == bar):'],
          'bad_lines': ['if(1 == 2):', 'while(foo == bar):']},
         {'pattern': ", [)]",
-         'description': 'Unnecessary whitespace between "," and ")"'},
+         'description': 'Unnecessary whitespace between "," and ")"',
+         'good_lines': ['foo = (1, 2, 3,)', 'foo(bar, 42)'],
+         'bad_lines': ['foo = (1, 2, 3, )']},
         {'pattern': "%  [(]",
-         'description': 'Unnecessary whitespace between "%" and "("'},
+         'description': 'Unnecessary whitespace between "%" and "("',
+         'good_lines': ['"foo %s bar" % ("baz",)'],
+         'bad_lines': ['"foo %s bar" %  ("baz",)']},
         # This next check could have false positives, but it seems pretty
         # rare; if we find any, they can be added to the exclude list for
         # this rule.
@@ -300,20 +310,31 @@ def build_custom_checkers(by_lang):
          'exclude_line': set([
              ('tools/tests/test_template_parser.py', '{% foo'),
          ]),
-         'description': 'Used % comprehension without a tuple'},
+         'description': 'Used % comprehension without a tuple',
+         'good_lines': ['"foo %s bar" % ("baz",)'],
+         'bad_lines': ['"foo %s bar" % "baz"']},
         {'pattern': '.*%s.* % \([a-zA-Z0-9_."\']*\)$',
-         'description': 'Used % comprehension without a tuple'},
+         'description': 'Used % comprehension without a tuple',
+         'good_lines': ['"foo %s bar" % ("baz",)"'],
+         'bad_lines': ['"foo %s bar" % ("baz")']},
         {'pattern': 'django.utils.translation',
          'include_only': set(['test/']),
-         'description': 'Test strings should not be tagged for translationx'},
+         'description': 'Test strings should not be tagged for translation',
+         'good_lines': [''],
+         'bad_lines': ['django.utils.translation']},
         {'pattern': 'userid',
-         'description': 'We prefer user_id over userid.'},
+         'description': 'We prefer user_id over userid.',
+         'good_lines': ['id = alice.user_id'],
+         'bad_lines': ['id = alice.userid']},
         {'pattern': 'json_success\({}\)',
-         'description': 'Use json_success() to return nothing'},
-        # To avoid json_error(_variable) and json_error(_(variable))
+         'description': 'Use json_success() to return nothing',
+         'good_lines': ['return json_success()'],
+         'bad_lines': ['return json_success({})']},
         {'pattern': '\Wjson_error\(_\(?\w+\)',
          'exclude': set(['zerver/tests']),
-         'description': 'Argument to json_error should be a literal string enclosed by _()'},
+         'description': 'Argument to json_error should be a literal string enclosed by _()',
+         'good_lines': ['return json_error(_("string"))'],
+         'bad_lines': ['return json_error(_variable)', 'return json_error(_(variable))']},
         {'pattern': '\Wjson_error\([\'"].+[),]$',
          'exclude': set(['zerver/tests']),
          'exclude_line': set([