diff --git a/.github/workflows/dependency-review.yml b/.github/workflows/dependency-review.yml
index 8f566971..cd5dcb36 100644
--- a/.github/workflows/dependency-review.yml
+++ b/.github/workflows/dependency-review.yml
@@ -6,10 +6,6 @@ on:
 permissions:
   contents: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
-  cancel-in-progress: true
-
 jobs:
   dependency-review:
     name: Dependency Review
diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index 865e8394..1c0a93a8 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -9,10 +9,6 @@ on:
 permissions:
   contents: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
-  cancel-in-progress: true
-
 jobs:
   docs:
     name: Docs
diff --git a/.github/workflows/pr-title.yml b/.github/workflows/pr-title.yml
index 155c3ade..e50e455d 100644
--- a/.github/workflows/pr-title.yml
+++ b/.github/workflows/pr-title.yml
@@ -8,10 +8,6 @@ on:
 permissions:
   pull-requests: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
-  cancel-in-progress: true
-
 jobs:
   validate:
     name: Validate PR title
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f0c8502d..7272e2ab 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -9,10 +9,6 @@ on:
 permissions:
   contents: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
-  cancel-in-progress: true
-
 jobs:
   test:
     name: Test
diff --git a/AGENTS.md b/AGENTS.md
index 5ef1cd4d..5993b7b5 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -259,6 +259,15 @@ workflow from `master`, so the PR still reports the old name. `Prepare release`
 also matches the `Test` workflow by its top-level `name:`, so renaming the
 workflow stops release planning without failing any check.
 
+The `Test`, `Documentation`, `PR Title`, and `Dependency Review` workflows have
+no `concurrency` block, so GitHub does not cancel their runs. Duplicate events
+on one PR head, such as a reopen or an edit right after a push, start duplicate
+runs of the required checks, and every run must finish. A cancelled run on the
+head turns the commit's check rollup to `FAILURE`. Do not add a `concurrency`
+group to these workflows. By default a group cancels a pending run when a newer
+run joins it, even with `cancel-in-progress: false`. Runs for a superseded head
+also finish. They cost CI minutes but block nothing.
+
 Recovery is for the owner. Agents never dispatch release workflows. The release
 stage accepts only the refs below, re-derives and re-verifies the release commit
 from the PR on each, and re-running a published version verifies it and changes