diff --git a/features/targets/go/node.py b/features/targets/go/node.py
index 987a050f..b3338fea 100644
--- a/features/targets/go/node.py
+++ b/features/targets/go/node.py
@@ -1,8 +1,12 @@
+"""Fixture source modeling a Go AST node for CST/AST refactoring tests."""
+
 from collections.abc import Sequence
 from typing import Any, Self
 
 
 class GoAstNode:
+    """Base node type exposing Go AST children, properties, and rewrite metadata."""
+
     # direct access protocol
     expr: Self
     body: Sequence[Self]
@@ -15,10 +19,10 @@ class GoAstNode:
 
     @property
     def properties(self) -> dict[str, Any]:
+        """Return the rewrite metadata (length, offset, name) for this node."""
         return {"length": self.length, "offset": self.offset, "name": self.name}
 
-    children: list[Self] = []
-
     @property
     def children(self) -> list[Self]:
+        """Return this node's direct child nodes (expr, body, other)."""
         return [self.expr, self.body, self.other]
diff --git a/pyproject.toml b/pyproject.toml
index 44faff4d..fcff3ae4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -95,9 +95,11 @@ skip_covered = false
 line-length = 140
 src = ["src", "test", "features"]
 extend-exclude = [
-    "features/targets/invalid.py",
-    "features/targets/taut/taut_test.py",  # legacy fixture source, not real code
-    "features/targets/go/node.py",  # legacy fixture source, not real code
+    "features/targets/taut/taut_test.py",  # legacy example, not real code
+    "features/targets/invalid.py",  # deliberately invalid Python (syntax errors); per docs/developer/
+                                    # coding-conventions.md we prefer line-based `# noqa` suppression,
+                                    # but invalid-syntax has no rule code so it can't be suppressed
+                                    # that way (or via per-file-ignores) — file-level exclusion only
 ]
 force-exclude = true