diff --git a/taxcalc/parameters.py b/taxcalc/parameters.py
index aaf25f7a8..dfd2c0291 100644
--- a/taxcalc/parameters.py
+++ b/taxcalc/parameters.py
@@ -506,18 +506,23 @@ def get_index_rate(self, param, label_to_extend_val):
 
     def set_rates(self):
         """
-        This method is implemented by classes inheriting
-        Parameters.
+        This method is implemented by classes inheriting Parameters.
         """
         raise NotImplementedError()
 
     def wage_growth_rates(self, year=None):
+        """
+        Return wage growth rates used in parameter indexing.
+        """
         if year is not None:
             syr = max(self.start_year, self._gfactors.first_year)
             return self._wage_growth_rates[year - syr]
         return self._wage_growth_rates or []
 
     def inflation_rates(self, year=None):
+        """
+        Return price inflation rates used in parameter indexing.
+        """
         if year is not None:
             syr = max(self.start_year, self._gfactors.first_year)
             return self._inflation_rates[year - syr]
@@ -665,30 +670,37 @@ def _update(self, revision, print_warnings, raise_errors):
         )
 
     def set_year(self, year):
+        """Specify parameter year"""
         self.set_state(year=year)
 
     @property
     def current_year(self):
+        """Propery docstring"""
         return self.label_grid["year"][0]
 
     @property
     def start_year(self):
+        """Propery docstring"""
         return self._stateless_label_grid["year"][0]
 
     @property
     def end_year(self):
+        """Propery docstring"""
         return self._stateless_label_grid["year"][-1]
 
     @property
     def num_years(self):
+        """Propery docstring"""
         return self.end_year - self.start_year + 1
 
     @property
     def parameter_warnings(self):
+        """Propery docstring"""
         return self.errors or {}
 
     @property
     def parameter_errors(self):
+        """Propery docstring"""
         return self.errors or {}
 
     @staticmethod
@@ -760,6 +772,9 @@ def convert_year_to_int(syr_dict):
         return convert_year_to_int(single_dict)
 
     def metadata(self):
+        """
+        Return parameter specification.
+        """
         return self.specification(meta_data=True, use_state=False)
 
     @staticmethod
diff --git a/taxcalc/tests/conftest.py b/taxcalc/tests/conftest.py
index e75ce4545..631911f94 100644
--- a/taxcalc/tests/conftest.py
+++ b/taxcalc/tests/conftest.py
@@ -16,57 +16,55 @@
 
 @pytest.fixture
 def skip_jit(monkeypatch):
+    """Fixture docstring"""
     monkeypatch.setenv("TESTING", "True")
     yield
 
 
 @pytest.fixture(scope='session')
 def tests_path():
+    """Fixture docstring"""
     return os.path.abspath(os.path.dirname(__file__))
 
 
 @pytest.fixture(scope='session')
 def cps_path(tests_path):
+    """Fixture docstring"""
     return os.path.join(tests_path, '..', 'cps.csv.gz')
 
 
 @pytest.fixture(scope='session')
 def cps_fullsample(cps_path):
+    """Fixture docstring"""
     return pandas.read_csv(cps_path)
 
 
 @pytest.fixture(scope='session')
 def cps_subsample(cps_fullsample):
+    """Fixture docstring"""
     # draw smaller cps.csv subsample than in test_cpscsv.py
     return cps_fullsample.sample(frac=0.01, random_state=123456789)
 
 
 @pytest.fixture(scope='session')
 def puf_path(tests_path):
+    """Fixture docstring"""
     return os.path.join(tests_path, '..', '..', 'puf.csv')
 
 
 @pytest.fixture(scope='session')
 def puf_fullsample(puf_path):
+    """Fixture docstring"""
     return pandas.read_csv(puf_path)
 
 
 @pytest.fixture(scope='session')
 def puf_subsample(puf_fullsample):
+    """Fixture docstring"""
     # draw same puf.csv subsample as in test_pufcsv.py
     return puf_fullsample.sample(frac=0.05, random_state=2222)
 
 
-@pytest.fixture(scope='session')
-def tmd_path(tests_path):
-    return os.path.join(tests_path, '..', '..', 'tmd.csv')
-
-
-@pytest.fixture(scope='session')
-def tmd_fullsample(tmd_path):
-    return pandas.read_csv(tmd_path)
-
-
 @pytest.fixture(scope='session', name='test_reforms_init')
 def fixture_test_reforms(tests_path):
     """
diff --git a/taxcalc/tests/test_consumption.py b/taxcalc/tests/test_consumption.py
index 157823fe7..86144dad1 100644
--- a/taxcalc/tests/test_consumption.py
+++ b/taxcalc/tests/test_consumption.py
@@ -13,10 +13,12 @@
 
 
 def test_start_year_consistency():
+    """Test docstring"""
     assert Consumption.JSON_START_YEAR == Policy.JSON_START_YEAR
 
 
 def test_validity_of_consumption_vars_set():
+    """Test docstring"""
     records_varinfo = Records(data=None)
     assert Consumption.RESPONSE_VARS.issubset(records_varinfo.USABLE_READ_VARS)
     useable_vars = set(['housing', 'snap', 'tanf', 'vet', 'wic',
@@ -25,6 +27,7 @@ def test_validity_of_consumption_vars_set():
 
 
 def test_update_consumption():
+    """Test docstring"""
     consump = Consumption()
     consump.update_consumption({})
     revision = {
@@ -61,6 +64,7 @@ def test_update_consumption():
 
 
 def test_incorrect_update_consumption():
+    """Test docstring"""
     with pytest.raises(paramtools.ValidationError):
         Consumption().update_consumption([])
     with pytest.raises(paramtools.ValidationError):
@@ -78,6 +82,7 @@ def test_incorrect_update_consumption():
 
 
 def test_future_update_consumption():
+    """Test docstring"""
     consump = Consumption()
     assert consump.current_year == consump.start_year
     assert consump.has_response() is False
@@ -101,6 +106,7 @@ def test_future_update_consumption():
 
 
 def test_consumption_default_data():
+    """Test docstring"""
     consump = Consumption()
     pdata = consump.specification(meta_data=True, ignore_state=True)
     for pname in pdata.keys():
@@ -111,6 +117,7 @@ def test_consumption_default_data():
 
 
 def test_consumption_response(cps_subsample):
+    """Test docstring"""
     # pylint: disable=too-many-locals
     consump = Consumption()
     mpc = 0.5
diff --git a/taxcalc/tests/test_decorators.py b/taxcalc/tests/test_decorators.py
index c80fa1758..05e53f199 100644
--- a/taxcalc/tests/test_decorators.py
+++ b/taxcalc/tests/test_decorators.py
@@ -17,6 +17,7 @@
 
 
 def test_create_apply_function_string():
+    """Test docstring"""
     ans = create_apply_function_string(['a', 'b', 'c'], ['d', 'e'], [])
     exp = ("def ap_func(x_0,x_1,x_2,x_3,x_4):\n"
            "  for i in range(len(x_0)):\n"
@@ -26,6 +27,7 @@ def test_create_apply_function_string():
 
 
 def test_create_apply_function_string_with_params():
+    """Test docstring"""
     ans = create_apply_function_string(['a', 'b', 'c'], ['d', 'e'], ['d'])
     exp = ("def ap_func(x_0,x_1,x_2,x_3,x_4):\n"
            "  for i in range(len(x_0)):\n"
@@ -35,6 +37,7 @@ def test_create_apply_function_string_with_params():
 
 
 def test_create_toplevel_function_string_mult_outputs():
+    """Test docstring"""
     ans = create_toplevel_function_string(['a', 'b'], ['d', 'e'],
                                           ['pm', 'pm', 'pf', 'pm'])
     exp = ''
@@ -59,6 +62,7 @@ def test_create_toplevel_function_string_mult_outputs():
 
 
 def test_create_toplevel_function_string():
+    """Test docstring"""
     ans = create_toplevel_function_string(['a'], ['d', 'e'],
                                           ['pm', 'pf', 'pm'])
     exp = ''
@@ -82,12 +86,14 @@ def test_create_toplevel_function_string():
 
 
 def some_calc(x, y, z):
+    """Function docstring"""
     a = x + y
     b = x + y + z
     return (a, b)
 
 
 def test_make_apply_function():
+    """Test docstring"""
     ans_do_jit = make_apply_function(some_calc, ['a', 'b'], ['x', 'y', 'z'],
                                      [], do_jit=True, no_python=True)
     assert ans_do_jit
@@ -98,12 +104,14 @@ def test_make_apply_function():
 
 @apply_jit(["a", "b"], ["x", "y", "z"], nopython=True)
 def magic_calc(x, y, z):
+    """Function docstring"""
     a = x + y
     b = x + y + z
     return (a, b)
 
 
 def magic(pm, pf):
+    """Function docstring"""
     # Adjustments
     outputs = pf.a, pf.b = magic_calc(pm, pf)
     header = ['a', 'b']
@@ -112,18 +120,21 @@ def magic(pm, pf):
 
 @iterate_jit(nopython=True)
 def magic_calc2(x, y, z):
+    """Function docstring"""
     a = x + y
     b = x + y + z
     return (a, b)
 
 
 class Foo:
+    """Foo class"""
     # pylint: disable=too-few-public-methods,too-many-instance-attributes
     pass
 
 
 @iterate_jit(nopython=True)
 def faux_function(mars):
+    """Function docstring"""
     if mars == 1:
         var = 2
     else:
@@ -133,15 +144,18 @@ def faux_function(mars):
 
 @iterate_jit(nopython=True)
 def ret_everything(a, b, c, d, e, f):
+    """Function docstring"""
     # pylint: disable=too-many-arguments,too-many-positional-arguments
     c = a + b
     d = a + b
     e = a + b
     f = a + b
-    return (c, d, e, f)
+    return (c, d, e,
+            f)
 
 
 def test_magic_apply_jit():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pm.a = np.ones((5,))
@@ -155,6 +169,7 @@ def test_magic_apply_jit():
 
 
 def test_magic_apply_jit_swap():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pm.a = np.ones((5,))
@@ -168,6 +183,7 @@ def test_magic_apply_jit_swap():
 
 
 def test_magic_iterate_jit():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pm.a = np.ones((1, 5))
@@ -181,6 +197,7 @@ def test_magic_iterate_jit():
 
 
 def test_faux_function_iterate_jit():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pf.mars = np.ones((5,))
@@ -191,6 +208,7 @@ def test_faux_function_iterate_jit():
 
 
 def test_ret_everything_iterate_jit():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pf.a = np.ones((5,))
@@ -207,12 +225,14 @@ def test_ret_everything_iterate_jit():
 
 @iterate_jit(nopython=True)
 def magic_calc3(x, y, z):
+    """Function docstring"""
     a = x + y
     b = a + z
     return (a, b)
 
 
 def test_function_takes_kwarg():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pm.a = np.ones((1, 5))
@@ -228,12 +248,14 @@ def test_function_takes_kwarg():
 
 @iterate_jit(nopython=True)
 def magic_calc4(x, y, z):
+    """Function docstring"""
     a = x + y
     b = a + z
     return (a, b)
 
 
 def test_function_no_parameters_listed():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pm.a = np.ones((1, 5))
@@ -249,12 +271,14 @@ def test_function_no_parameters_listed():
 
 @iterate_jit(parameters=['w'], nopython=True)
 def magic_calc5(w, x, y, z):
+    """Function docstring"""
     a = x + y
     b = w[0] + x + y + z
     return (a, b)
 
 
 def test_function_parameters_optional():
+    """Test docstring"""
     pm = Foo()
     pf = Foo()
     pm.a = np.ones((1, 5))
@@ -270,23 +294,27 @@ def test_function_parameters_optional():
 
 
 def unjittable_function1(w, x, y, z):
+    """Function docstring"""
     a = x + y
     b = w[0] + x + y + z
 
 
 def unjittable_function2(w, x, y, z):
+    """Function docstring"""
     a = x + y
     b = w[0] + x + y + z
     return (a, b, c)
 
 
 def test_iterate_jit_raises_on_no_return():
+    """Test docstring"""
     with pytest.raises(ValueError):
         ij = iterate_jit(parameters=['w'], nopython=True)
         ij(unjittable_function1)
 
 
 def test_iterate_jit_raises_on_unknown_return_argument():
+    """Test docstring"""
     ij = iterate_jit(parameters=['w'], nopython=True)
     uf2 = ij(unjittable_function2)
     pm = Foo()
@@ -302,6 +330,7 @@ def test_iterate_jit_raises_on_unknown_return_argument():
 
 
 def magic_calc6(w, x, y, z):
+    """Function docstring"""
     a = x + y
     b = w[0] + x + y + z
     return (a, b)
diff --git a/taxcalc/tests/test_growdiff.py b/taxcalc/tests/test_growdiff.py
index e9877f913..611512a50 100644
--- a/taxcalc/tests/test_growdiff.py
+++ b/taxcalc/tests/test_growdiff.py
@@ -13,10 +13,12 @@
 
 
 def test_start_year_consistency():
+    """Test docstring"""
     assert GrowDiff.JSON_START_YEAR == Policy.JSON_START_YEAR
 
 
 def test_update_and_apply_growdiff():
+    """Test docstring"""
     gdiff = GrowDiff()
     # update GrowDiff instance
     diffs = {
@@ -45,6 +47,7 @@ def test_update_and_apply_growdiff():
 
 
 def test_has_any_response():
+    """Test docstring"""
     start_year = GrowDiff.JSON_START_YEAR
     gdiff = GrowDiff()
     assert gdiff.current_year == start_year
diff --git a/taxcalc/tests/test_parameters.py b/taxcalc/tests/test_parameters.py
index 46ec67127..bb0404811 100644
--- a/taxcalc/tests/test_parameters.py
+++ b/taxcalc/tests/test_parameters.py
@@ -297,6 +297,7 @@ def test_parameters_mentioned(tests_path, jfname, pfname):
 # following tests access private methods, so pylint: disable=protected-access
 
 class ArrayParams(Parameters):
+    """ArrayParams class"""
     defaults = {
         "schema": {
             "labels": {
@@ -416,6 +417,7 @@ def test_expand_xd_errors():
 
 
 def test_expand_empty():
+    """Test docstring"""
     params = ArrayParams(label_to_extend=None, array_first=False)
     params.sort_values()
     one_dim = copy.deepcopy(params.one_dim)
@@ -427,6 +429,7 @@ def test_expand_empty():
 
 
 def test_expand_1d_scalar():
+    """Test docstring"""
     yrs = 12
     val = 10.0
     exp = np.array([val * math.pow(1.02, i) for i in range(0, yrs)])
diff --git a/taxcalc/tests/test_records.py b/taxcalc/tests/test_records.py
index 6dd0131d6..498963d2d 100644
--- a/taxcalc/tests/test_records.py
+++ b/taxcalc/tests/test_records.py
@@ -16,6 +16,7 @@
 
 
 def test_incorrect_records_instantiation(cps_subsample):
+    """Test docstring"""
     with pytest.raises(ValueError):
         recs = Records(data=[])
     with pytest.raises(ValueError):
@@ -31,6 +32,7 @@ def test_incorrect_records_instantiation(cps_subsample):
 
 
 def test_correct_records_instantiation(cps_subsample):
+    """Test docstring"""
     rec1 = Records.cps_constructor(data=cps_subsample, gfactors=None)
     assert rec1
     assert np.all(rec1.MARS != 0)
@@ -55,6 +57,7 @@ def test_correct_records_instantiation(cps_subsample):
 
 
 def test_read_cps_data(cps_fullsample):
+    """Test docstring"""
     data = Records.read_cps_data()
     assert data.equals(cps_fullsample)
 
@@ -118,12 +121,14 @@ def test_read_cps_data(cps_fullsample):
     )
 ])
 def test_read_data(csv):
+    """Test docstring"""
     df = pd.read_csv(StringIO(csv))
     with pytest.raises(ValueError):
         Records(data=df)
 
 
 def test_for_duplicate_names():
+    """Test docstring"""
     records_varinfo = Records(data=None)
     varnames = set()
     for varname in records_varinfo.USABLE_READ_VARS:
diff --git a/taxcalc/tests/test_taxcalcio.py b/taxcalc/tests/test_taxcalcio.py
index 93d7a5f59..a0327be08 100644
--- a/taxcalc/tests/test_taxcalcio.py
+++ b/taxcalc/tests/test_taxcalcio.py
@@ -746,6 +746,7 @@ def fixture_regression_reform_file():
 
 
 def test_error_message_parsed_correctly(regression_reform_file):
+    """Test docstring"""
     tcio = TaxCalcIO(input_data=pd.read_csv(StringIO(RAWINPUT)),
                      tax_year=2022,
                      baseline=regression_reform_file.name,