diff --git a/actions/github/should-run/action.yml b/actions/github/should-run/action.yml
index a891d34c3a..491c9779d3 100644
--- a/actions/github/should-run/action.yml
+++ b/actions/github/should-run/action.yml
@@ -10,9 +10,12 @@ inputs:
     default: ${{ github.base_ref }}
   checkout-repo:
     description: >
-      Boolean flag to control whether the action should check out the repo
-    default: true
-    type: boolean
+      Whether this action should perform its own full (fetch-depth: 0) checkout.
+      Defaults to "false"; the caller is expected to have already checked out
+      the repository with sufficient history for the diff. Set to "true" to have
+      this action perform its own checkout (this will clean the working tree and
+      remove any untracked files produced by earlier job steps).
+    default: "false"
   config:
     description: >
       YAML paths configuration. Can be a list of paths, or an object with keys like 'paths' and 'push'.
@@ -38,7 +41,7 @@ runs:
   using: composite
   steps:
   - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
-    if: inputs.checkout-repo
+    if: inputs.checkout-repo == 'true'
     with:
       fetch-depth: 0
   - uses: envoyproxy/toolshed/actions/bson@7f2aff965c314c8a80a09a48f61552b1a3337af1
diff --git a/actions/github/should-run/tests/checkout-repo-false-preserves-tree.test.yml b/actions/github/should-run/tests/checkout-repo-false-preserves-tree.test.yml
new file mode 100644
index 0000000000..8b11a59be2
--- /dev/null
+++ b/actions/github/should-run/tests/checkout-repo-false-preserves-tree.test.yml
@@ -0,0 +1,22 @@
+uses: ./actions/github/should-run
+id: should-run
+with:
+  checkout-repo: "false"
+  config: |
+    paths:
+    - some/path
+
+before:
+- shell: bash
+  run: |
+    echo "marker-content" > .should-run-untracked-marker
+
+after:
+- shell: bash
+  run: |
+    if [[ ! -f ".should-run-untracked-marker" ]]; then
+        echo "fail:Untracked marker file was removed — checkout ran despite checkout-repo: false" >> "$TEST_OUTPUT"
+    else
+        echo "success:Untracked marker file preserved — no checkout occurred with checkout-repo: false" >> "$TEST_OUTPUT"
+    fi
+    rm -f .should-run-untracked-marker
diff --git a/actions/github/should-run/tests/default-does-not-checkout.test.yml b/actions/github/should-run/tests/default-does-not-checkout.test.yml
new file mode 100644
index 0000000000..2a973b1ff0
--- /dev/null
+++ b/actions/github/should-run/tests/default-does-not-checkout.test.yml
@@ -0,0 +1,21 @@
+uses: ./actions/github/should-run
+id: should-run
+with:
+  config: |
+    paths:
+    - some/path
+
+before:
+- shell: bash
+  run: |
+    echo "marker-content" > .should-run-default-marker
+
+after:
+- shell: bash
+  run: |
+    if [[ ! -f ".should-run-default-marker" ]]; then
+        echo "fail:Untracked marker file was removed — checkout ran with default checkout-repo" >> "$TEST_OUTPUT"
+    else
+        echo "success:Untracked marker file preserved — default checkout-repo does not checkout" >> "$TEST_OUTPUT"
+    fi
+    rm -f .should-run-default-marker
diff --git a/actions/github/should-run/tests/paths-match.test.yml b/actions/github/should-run/tests/paths-match.test.yml
new file mode 100644
index 0000000000..5bf1e5b636
--- /dev/null
+++ b/actions/github/should-run/tests/paths-match.test.yml
@@ -0,0 +1,29 @@
+uses: ./actions/github/should-run
+id: should-run
+with:
+  checkout-repo: "false"
+  config: |
+    paths:
+    - tmp-should-run-test/**
+
+before:
+- shell: bash
+  run: |
+    mkdir -p tmp-should-run-test
+    echo "test" > tmp-should-run-test/file.txt
+    git add tmp-should-run-test/file.txt
+    git -c user.name="Test" -c user.email="test@test.com" commit -m "tmp: add test file for should-run paths test"
+
+after:
+- shell: bash
+  run: |
+    RUN_OUTPUT='${{ steps.should-run.outputs.run }}'
+    if [[ "$RUN_OUTPUT" != "true" ]]; then
+        echo "fail:Expected run=true for matching path, got '$RUN_OUTPUT'" >> "$TEST_OUTPUT"
+    else
+        echo "success:run=true for matching path tmp-should-run-test/**" >> "$TEST_OUTPUT"
+    fi
+    # Clean up the temporary commit and file
+    git reset HEAD~1 --soft
+    git restore --staged tmp-should-run-test/file.txt || true
+    rm -rf tmp-should-run-test