diff --git a/conftest.py b/conftest.py
new file mode 100644
index 0000000..88fe65b
--- /dev/null
+++ b/conftest.py
@@ -0,0 +1,11 @@
+from pytest import Config
+
+
+def pytest_configure(config: Config):
+    """
+    Registers a new mark 'final' that can be applied to tests.
+
+    I did not want to add these in pyproject.toml.
+    """
+
+    config.addinivalue_line("markers", "final: the final test")
diff --git a/justfile b/justfile
index 9aec35a..3d77840 100644
--- a/justfile
+++ b/justfile
@@ -41,6 +41,9 @@ update-deps:
 
 # Run tests, ARGS are passed-through to pytest
 test *ARGS:
+  uv run pytest tests.py -m "not final" {{ ARGS }}
+
+alltests *ARGS:
   uv run pytest tests.py {{ ARGS }}
 
 # run tests and create coverage reports
diff --git a/mise.toml b/mise.toml
index ffbd3a8..ca3c768 100644
--- a/mise.toml
+++ b/mise.toml
@@ -3,6 +3,7 @@
 DATABASE_URL = "sqlite:///database.db"
 
 [tools]
+difftastic = "latest"
 markdownlint-cli2 = "latest"
 prek = "latest"
 python = "3.14"
diff --git a/pyproject.toml b/pyproject.toml
index d4c43ed..c0b2f35 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -64,6 +64,7 @@ omit = ["tests.py"]
 source_dirs = ["src/"]
 
 [tool.pytest]
+# custom marks are created in conftest.py
 asyncio_mode = "auto"
 
 [tool.ruff]
diff --git a/src/teilchensammler_cli/models.py b/src/teilchensammler_cli/models.py
index f72650e..77619a8 100644
--- a/src/teilchensammler_cli/models.py
+++ b/src/teilchensammler_cli/models.py
@@ -21,7 +21,7 @@ class TeilchenCreate(SQLModel):
 
 
 class Teilchen(TeilchenCreate, table=True):
-    id: uuid.UUID = Field(default_factory=uuid.uuid7, primary_key=True)  # ty:ignore[unresolved-attribute]
+    id: uuid.UUID = Field(default_factory=uuid.uuid7, primary_key=True)
 
 
 async def make_teilchen_input(text: str) -> TeilchenCreate | None:
@@ -59,7 +59,7 @@ async def make_teilchen_input(text: str) -> TeilchenCreate | None:
     description_start = text.find('"', name_end + 1)
     description_end = text.find('"', description_start + 1)
     if description_end > description_start:
-        description = text[description_start:description_end]
+        description = text[description_start + 1 : description_end]
     else:
         description = ""
 
diff --git a/tests.py b/tests.py
index 0b547c6..b4a3f08 100644
--- a/tests.py
+++ b/tests.py
@@ -1,4 +1,3 @@
-from typing import TypedDict
 import pytest
 import logging
 
@@ -7,23 +6,14 @@ from teilchensammler_cli.models import TeilchenCreate, make_teilchen_input
 logger = logging.getLogger(__name__)
 
 
+@pytest.mark.final  # don't run while we are fiddling with the app
 def test_initial_layout(snap_compare):
     from teilchensammler_cli.main import app
 
     assert snap_compare(app, terminal_size=(130, 40))
 
 
-class Teilchen(TypedDict):
-    """The things I do for my LSP..."""
-
-    name: str
-    description: str
-    tags: str
-    text: str
-    number: int
-
-
-empty_teilchen: Teilchen = {
+empty_teilchen = {
     "name": "",
     "description": "",
     "tags": "",
@@ -32,23 +22,62 @@ empty_teilchen: Teilchen = {
 }
 
 
+def TC(**kwargs) -> TeilchenCreate | None:
+    """TC = TeilchenCreate
+
+    Create Teilchen with desired attributes.
+
+    Args:
+        input: mapping that must be well-formed enough to actually create a Teilchen
+
+    Returns:
+        - `None` on empty input
+        - an instance of `TeilchenCreate`
+    """
+    if kwargs:
+        arguments = empty_teilchen | kwargs
+        return TeilchenCreate(**arguments)  # ty:ignore[invalid-argument-type]
+
+
 @pytest.mark.parametrize(
     "example_input,expected",
     [
-        ("", None),
-        ("a", None),
-        ("a.", {"name": "a", "text": "a."}),
-        ("aa", None),
-        ("aa.", {"name": "aa", "text": "aa."}),
+        # Not enough data
+        ("", TC()),
+        (".", TC()),
+        ("..", TC()),
+        (".a.", TC()),
+        ("a", TC()),
+        ("aa", TC()),
+        # Just enough for "name"
+        ("a.", TC(name="a", text="a.")),
+        ("aa.", TC(name="aa", text="aa.")),
+        ("a..", TC(name="a", text="a..")),
+        ("a.b.", TC(name="a", text="a.b.")),
+        # Just enough for "name" and "description"
+        ('a."b"', TC(name="a", description="b", text='a."b"')),
+        ('a. "b"', TC(name="a", description="b", text='a. "b"')),
+        ('a. ""', TC(name="a", description="", text='a. ""')),
+        ('. ""', TC()),
+        ('. "b"', TC()),
+        # Just enough for "name" and "description" and "tags"
+        ('a. "b" #c', TC(name="a", description="b", tags="#c", text='a. "b" #c')),
+        ('a. "b #d" #c', TC(name="a", description="b #d", tags="#c #d", text='a. "b #d" #c')),
+        # swap order in input, tag result is stable
+        ('a. "b #c" #d', TC(name="a", description="b #c", tags="#c #d", text='a. "b #c" #d')),
+        # Just enough for "name" and "tags"
+        ("a. #d", TC(name="a", description="", tags="#d", text="a. #d")),
+        ("a. #d#b", TC(name="a", description="", tags="#b #d", text="a. #d#b")),
+        ("a. ##b", TC(name="a", description="", tags="#b", text="a. ##b")),
+        ("a. #", TC(name="a", description="", tags="", text="a. #")),
+        ("a. ##", TC(name="a", description="", tags="", text="a. ##")),
+        # do we care about "number"?
     ],
 )
-async def test_teilchendata_must_include_period(
+async def test_maketeilcheninput_can_create_desired_teilchen(
     example_input: str, expected: dict[str, str | int] | None
 ) -> None:
 
-    thing = expected
-    if expected:
-        arguments = empty_teilchen | expected
-        thing = TeilchenCreate(**arguments)  # ty:ignore[invalid-argument-type]
+    actual = await make_teilchen_input(example_input)
 
-    assert await make_teilchen_input(example_input) == thing
+    assert expected == actual
diff --git a/uv.lock b/uv.lock
index d2b5c5a..9ece310 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1161,7 +1161,6 @@ dependencies = [
     { name = "orjson" },
     { name = "sqlmodel" },
     { name = "textual" },
-    { name = "textual-dev" },
 ]
 
 [package.dev-dependencies]
@@ -1171,6 +1170,7 @@ dev = [
     { name = "pytest-asyncio" },
     { name = "pytest-cov" },
     { name = "pytest-textual-snapshot" },
+    { name = "textual-dev" },
     { name = "twine" },
 ]
 
@@ -1181,7 +1181,6 @@ requires-dist = [
     { name = "orjson", specifier = ">=3.11.4" },
     { name = "sqlmodel", specifier = ">=0.0.27" },
     { name = "textual", specifier = ">=6.7.1" },
-    { name = "textual-dev", specifier = ">=1.8.0" },
 ]
 
 [package.metadata.requires-dev]
@@ -1191,6 +1190,7 @@ dev = [
     { name = "pytest-asyncio", specifier = ">=1.3.0" },
     { name = "pytest-cov", specifier = ">=7.0.0" },
     { name = "pytest-textual-snapshot", specifier = ">=1.0.0" },
+    { name = "textual-dev", specifier = ">=1.8.0" },
     { name = "twine", specifier = ">=6.2.0" },
 ]