diff --git a/scripts/pre_commit_lint.sh b/scripts/pre_commit_lint.sh
index d38a0eee3de..ad1b4e793ab 100755
--- a/scripts/pre_commit_lint.sh
+++ b/scripts/pre_commit_lint.sh
@@ -12,6 +12,8 @@
 #   - litellm/ Python  -> `make lint` (test-linting.yml's lint job)
 #   - tests/e2e Python -> `make lint-e2e-basedpyright` (test-linting.yml's e2e type-check step)
 #                         + raw HTTP client ban (test-code-quality.yml's check_e2e_no_raw_requests)
+#   - tests/ Python    -> ruff over ruff-tests.toml + `make lint-test-quality` (test-linting.yml's
+#                         test-tree ruff and test-quality budget steps)
 #   - dashboard        -> prettier + eslint + lint budgets (test-litellm-ui-build.yml's frontend-lint)
 #   - proxy/types      -> regenerate the lazy OpenAPI snapshot and dashboard API types, fail on drift (check-ui-api-types.yml)
 #
@@ -88,15 +90,18 @@ existing_files() {
 
 litellm_py_pattern='^litellm/.*\.py$'
 e2e_py_pattern='^tests/e2e/.*\.py$'
+tests_py_pattern='^tests/.*\.py$'
 spec_pattern='^(litellm/(proxy|types)/.*|ui/litellm-dashboard/(scripts/gen-api-types\.mjs|package\.json|package-lock\.json|src/lib/http/schema\.d\.ts))$'
 ui_prettier_pattern='^ui/litellm-dashboard/.*\.(js|jsx|ts|tsx|mjs|cjs|json|css|scss|md|mdx|yml|yaml|html)$'
 ui_eslint_pattern='^ui/litellm-dashboard/.*\.(js|jsx|ts|tsx|mjs|cjs)$'
 
-# CI's lint job (test-linting.yml) only inspects litellm/, so a tests-only or
-# scripts-only commit can't turn it red; scope the trigger there to skip the slow
-# make lint when it couldn't catch anything.
+# CI's lint job (test-linting.yml) is make lint: litellm/ checks plus two test-tree
+# steps (ruff over ruff-tests.toml and the test-quality budget). Trigger the slow
+# make lint on litellm/ files only; a tests-only commit runs just those two steps.
 litellm_py_files=$(scope_match "$litellm_py_pattern")
 e2e_py_files=$(scope_match "$e2e_py_pattern")
+tests_py_changed=$(scope_match "$tests_py_pattern")
+tests_py_files=$(printf '%s\n' "$tests_py_changed" | existing_files)
 # ruff format (and CI's format step) skip enterprise; the rest of make lint covers it.
 fmt_files=$(printf '%s\n' "$litellm_py_files" | grep -v '^litellm/enterprise/' | existing_files)
 # check-ui-api-types.yml triggers on any file under litellm/proxy or litellm/types
@@ -136,6 +141,7 @@ if [ -n "$staged" ]; then
     }
     warn_skipped "Python lint (make lint)" "$litellm_py_pattern" "$litellm_py_files"
     warn_skipped "tests/e2e checks (basedpyright + raw HTTP client ban)" "$e2e_py_pattern" "$e2e_py_files"
+    warn_skipped "test-tree lint (ruff-tests.toml + test-quality budget)" "$tests_py_pattern" "$tests_py_changed"
     warn_skipped "dashboard lint (prettier + eslint + lint budgets)" "$ui_prettier_pattern" "$ui_prettier_changed"
     warn_skipped "dashboard API-type sync (npm run gen:api)" "$spec_pattern" "$spec_files"
 fi
@@ -225,6 +231,16 @@ if [ -n "$e2e_py_files" ]; then
         || { echo "✗ Raw HTTP client import in tests/e2e. Route the call through tests/e2e/e2e_http.py, then re-run make check." >&2; status=1; }
 fi
 
+if [ -n "$tests_py_changed" ] && [ -z "$litellm_py_files" ]; then
+    if [ -n "$tests_py_files" ]; then
+        echo "check: linting the test tree (ruff check --config ruff-tests.toml, scoped tests files)"
+        printf '%s\n' "$tests_py_files" | xargs uv run --no-sync ruff check --config ruff-tests.toml \
+            || { echo "✗ Test-tree ruff failed. Fix the errors above, then re-run make check." >&2; status=1; }
+    fi
+    echo "check: checking the test-quality budget (make lint-test-quality)"
+    make lint-test-quality || { echo "✗ Test-quality budget failed. Fix the errors above, then re-run make check." >&2; status=1; }
+fi
+
 dashboard_checks() {
     echo "check: linting dashboard (prettier + eslint + lint budgets)"
     if [ ! -d ui/litellm-dashboard/node_modules ]; then
@@ -313,10 +329,11 @@ summary_item() {
 echo "check: summary"
 summary_item "Python lint (make lint)" "$litellm_py_files" "no litellm/ Python files in scope"
 summary_item "tests/e2e checks (basedpyright + raw HTTP client ban)" "$e2e_py_files" "no tests/e2e Python files in scope"
+summary_item "test-tree lint (ruff-tests.toml + test-quality budget)" "$tests_py_changed" "no tests/ Python files in scope"
 summary_item "dashboard lint (prettier + eslint + lint budgets)" "$ui_prettier_changed$ui_eslint_changed" "no dashboard files in scope"
 summary_item "dashboard API-type sync (npm run gen:api)" "$spec_files" "no litellm/proxy, litellm/types, or generator files in scope"
 
-if [ -z "$litellm_py_files$e2e_py_files$ui_prettier_changed$ui_eslint_changed$spec_files" ]; then
+if [ -z "$litellm_py_files$e2e_py_files$tests_py_changed$ui_prettier_changed$ui_eslint_changed$spec_files" ]; then
     echo "check: NOTE - no gating lint check matches the files in scope, so nothing ran:" >&2
     printf '%s\n' "$scope" | sed 's/^/    /' >&2
     echo "  A pass here is a no-op, not a lint verdict." >&2
diff --git a/tests/test_litellm/test_pre_commit_lint.py b/tests/test_litellm/test_pre_commit_lint.py
index aa2260e89ea..22ae0e1bfaa 100644
--- a/tests/test_litellm/test_pre_commit_lint.py
+++ b/tests/test_litellm/test_pre_commit_lint.py
@@ -40,6 +40,9 @@ case "$*" in
             sleep 60
         fi
         ;;
+    lint-test-quality)
+        [ "${STUB_FAIL:-}" = "test-quality" ] && exit 1
+        ;;
 esac
 exit 0
 """
@@ -69,6 +72,10 @@ case "$*" in
     *orjson*)
         [ -n "${STUB_BARRIER_DIR:-}" ] && barrier_sync genapi "python dashboard"
         ;;
+    "run --no-sync ruff check --config ruff-tests.toml"*)
+        [ -n "${STUB_ARGS_DIR:-}" ] && echo "$*" >> "$STUB_ARGS_DIR/ruff_tests.args"
+        [ "${STUB_FAIL:-}" = "tests-ruff" ] && exit 1
+        ;;
 esac
 exit 0
 """
@@ -153,6 +160,13 @@ def _set_base_ref(repo: Path) -> None:
     )
 
 
+def _stage_file(repo: Path, relative: str, body: str) -> None:
+    path = repo / relative
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(body)
+    subprocess.run(["git", "add", relative], cwd=repo, check=True)
+
+
 def test_nothing_staged_scopes_to_working_tree_diff_and_runs_checks(tmp_path: Path) -> None:
     repo, bin_dir = _sandbox(tmp_path)
     _commit_all(repo, "base")
@@ -405,6 +419,7 @@ def test_run_ends_with_a_summary_of_ran_and_skipped_blocks(tmp_path: Path) -> No
     assert "ran:     dashboard lint (prettier + eslint + lint budgets)" in proc.stdout
     assert "ran:     dashboard API-type sync (npm run gen:api)" in proc.stdout
     assert "skipped: tests/e2e checks (basedpyright + raw HTTP client ban) (no tests/e2e Python files in scope)" in proc.stdout
+    assert "skipped: test-tree lint (ruff-tests.toml + test-quality budget) (no tests/ Python files in scope)" in proc.stdout
     assert "check: PASS" in proc.stdout
     assert "check: FAIL" not in proc.stdout
 
@@ -412,20 +427,93 @@ def test_run_ends_with_a_summary_of_ran_and_skipped_blocks(tmp_path: Path) -> No
 def test_staged_files_matching_no_check_print_an_explicit_noop_note_and_nonempty_log(tmp_path: Path) -> None:
     repo, bin_dir = _sandbox(tmp_path)
     _commit_all(repo, "base")
-    tests_dir = repo / "tests" / "test_litellm"
-    tests_dir.mkdir(parents=True)
-    (tests_dir / "test_x.py").write_text("def test_x() -> None: ...\n")
-    subprocess.run(["git", "add", "tests"], cwd=repo, check=True)
+    _stage_file(repo, "scripts/tool.py", "def main() -> None: ...\n")
     proc = _run(repo, bin_dir, {})
     assert proc.returncode == 0, proc.stdout + proc.stderr
     assert "no gating lint check matches the files in scope, so nothing ran" in proc.stdout
-    assert "tests/test_litellm/test_x.py" in proc.stdout
+    assert "scripts/tool.py" in proc.stdout
     assert "a no-op, not a lint verdict" in proc.stdout
     assert "check: PASS" in proc.stdout
     assert "linting Python" not in proc.stdout
     log = (repo / ".git" / "pre_commit_lint.log").read_text()
     assert "check: summary" in log
     assert "skipped: Python lint (make lint) (no litellm/ Python files in scope)" in log
+    assert "skipped: test-tree lint (ruff-tests.toml + test-quality budget) (no tests/ Python files in scope)" in log
+
+
+def test_tests_only_change_runs_test_tree_ruff_on_staged_files_and_the_quality_gate(tmp_path: Path) -> None:
+    repo, bin_dir = _sandbox(tmp_path)
+    _commit_all(repo, "base")
+    args_dir = tmp_path / "args"
+    args_dir.mkdir()
+    _stage_file(repo, "tests/test_a.py", "def test_a() -> None: ...\n")
+    _stage_file(repo, "tests/test_b.py", "def test_b() -> None: ...\n")
+    _stage_file(repo, "tests/fixtures/data.json", "{}\n")
+    proc = _run(repo, bin_dir, {"STUB_ARGS_DIR": str(args_dir)})
+    assert proc.returncode == 0, proc.stdout + proc.stderr
+    ruff_args = (args_dir / "ruff_tests.args").read_text().splitlines()
+    assert ruff_args == ["run --no-sync ruff check --config ruff-tests.toml tests/test_a.py tests/test_b.py"]
+    assert "ran:     test-tree lint (ruff-tests.toml + test-quality budget)" in proc.stdout
+    assert "no gating lint check matches" not in proc.stdout
+    assert "linting Python" not in proc.stdout
+    assert "check: PASS" in proc.stdout
+
+
+@pytest.mark.parametrize(
+    ("fail", "message"),
+    [
+        ("tests-ruff", "Test-tree ruff failed"),
+        ("test-quality", "Test-quality budget failed"),
+    ],
+)
+def test_a_failing_test_tree_check_fails_a_tests_only_run(tmp_path: Path, fail: str, message: str) -> None:
+    repo, bin_dir = _sandbox(tmp_path)
+    _commit_all(repo, "base")
+    _stage_file(repo, "tests/test_a.py", "def test_a() -> None: ...\n")
+    proc = _run(repo, bin_dir, {"STUB_FAIL": fail})
+    assert proc.returncode == 1
+    assert message in proc.stdout + proc.stderr
+    assert "check: FAIL" in proc.stdout
+
+
+def test_tests_changed_alongside_litellm_files_defer_to_make_lint(tmp_path: Path) -> None:
+    repo, bin_dir = _sandbox(tmp_path)
+    _commit_all(repo, "base")
+    args_dir = tmp_path / "args"
+    args_dir.mkdir()
+    _stage_file(repo, "litellm/foo.py", "x = 2\n")
+    _stage_file(repo, "tests/test_a.py", "def test_a() -> None: ...\n")
+    proc = _run(repo, bin_dir, {"STUB_ARGS_DIR": str(args_dir), "STUB_FAIL": "test-quality"})
+    assert proc.returncode == 0, proc.stdout + proc.stderr
+    assert "linting Python" in proc.stdout
+    assert not (args_dir / "ruff_tests.args").exists()
+    assert "ran:     test-tree lint (ruff-tests.toml + test-quality budget)" in proc.stdout
+
+
+def test_deleted_test_file_still_runs_the_quality_gate_without_feeding_ruff_the_missing_file(tmp_path: Path) -> None:
+    repo, bin_dir = _sandbox(tmp_path)
+    _stage_file(repo, "tests/test_a.py", "def test_a() -> None: ...\n")
+    _commit_all(repo, "base")
+    args_dir = tmp_path / "args"
+    args_dir.mkdir()
+    subprocess.run(["git", "rm", "-q", "tests/test_a.py"], cwd=repo, check=True)
+    proc = _run(repo, bin_dir, {"STUB_ARGS_DIR": str(args_dir), "STUB_FAIL": "test-quality"})
+    assert proc.returncode == 1
+    assert "Test-quality budget failed" in proc.stdout + proc.stderr
+    assert not (args_dir / "ruff_tests.args").exists()
+
+
+def test_partial_staging_warns_when_test_files_are_left_unstaged(tmp_path: Path) -> None:
+    repo, bin_dir = _sandbox(tmp_path)
+    _stage_file(repo, "tests/test_a.py", "def test_a() -> None: ...\n")
+    _commit_all(repo, "base")
+    _stage_file(repo, "notes.md", "hi\n")
+    (repo / "tests" / "test_a.py").write_text("def test_a() -> None:\n    assert True\n")
+    proc = _run(repo, bin_dir, {})
+    assert proc.returncode == 0, proc.stdout + proc.stderr
+    assert "SKIPPED test-tree lint (ruff-tests.toml + test-quality budget)" in proc.stdout
+    assert "tests/test_a.py" in proc.stdout
+    assert "make lint-test-quality" not in proc.stdout
 
 
 def test_run_queues_through_the_machine_wide_gate_slot_lock(tmp_path: Path) -> None: