diff --git a/actions/changeset/check-coverage/action.yaml b/actions/changeset/check-coverage/action.yaml
index 07f97209..d5bdd78a 100644
--- a/actions/changeset/check-coverage/action.yaml
+++ b/actions/changeset/check-coverage/action.yaml
@@ -7,7 +7,8 @@ description: |
     - editing files inside a workspace package (e.g. block code under
       packages/<pkg>/) without adding that package to the changeset;
     - bumping a catalog version in pnpm-workspace.yaml without a matching
-      bump for the workflow packages that consume it via `catalog:`.
+      bump for packages that consume it as a runtime dependency via
+      `catalog:` (devDependencies / build-only tooling are not flagged).
 
   Runs after `pnpm install`. Requires the runner to have `pnpm`, `jq`, and
   `yq` (mikefarah, v4+) on PATH — all pre-installed on GitHub-hosted
diff --git a/actions/changeset/check-coverage/check-coverage.sh b/actions/changeset/check-coverage/check-coverage.sh
index a7ad8311..aa83adae 100755
--- a/actions/changeset/check-coverage/check-coverage.sh
+++ b/actions/changeset/check-coverage/check-coverage.sh
@@ -10,9 +10,18 @@
 #      git-diff check itself.
 #
 #   2. Catalog version bumps in pnpm-workspace.yaml: for each touched
-#      catalog key, find workspace packages that consume it via
+#      catalog key, find workspace packages that consume it as a *runtime*
+#      dependency (`dependencies` or `peerDependencies`) via
 #      `"<key>": "catalog:..."` and require those packages to bump.
 #
+#      devDependencies and optionalDependencies are intentionally NOT
+#      considered. A bump to build-only tooling (e.g. @platforma-sdk/block-tools
+#      in a block's model, @platforma-sdk/tengo-builder in its workflow) does
+#      not change the published artifact's runtime, and `pnpm changeset` does
+#      not flag those packages either. Requiring a bump for them produced
+#      false positives on PRs that only touched an unrelated package (e.g. the
+#      UI) but happened to carry a catalog bump for shared build tooling.
+#
 # Skips private (unpublished) workspace packages — they never appear in
 # the changeset's release set.
 #
@@ -186,8 +195,12 @@ if git diff --name-only "origin/${BASE_BRANCH}...HEAD" | grep -qx 'pnpm-workspac
         [ "${pkg_is_private[${name}]:-false}" = 'true' ] && continue
         pj="${pkg_name_to_dir[${name}]}/package.json"
         [ -f "${pj}" ] || continue
+        # Runtime sections only. devDependencies/optionalDependencies are
+        # excluded on purpose — bumping build-only tooling consumed via
+        # `catalog:` (block-tools, tengo-builder, …) doesn't alter the
+        # published runtime, so requiring a release for it is a false positive.
         if jq -e --arg k "${key}" '
-            [.dependencies?, .devDependencies?, .peerDependencies?, .optionalDependencies?]
+            [.dependencies?, .peerDependencies?]
             | map(select(. != null) | to_entries) | add // []
             | map(select(.key == $k and ((.value // "") | startswith("catalog:"))))
             | length > 0
diff --git a/actions/changeset/check-coverage/test/coverage.bats b/actions/changeset/check-coverage/test/coverage.bats
index 369a6d98..593eb3f1 100644
--- a/actions/changeset/check-coverage/test/coverage.bats
+++ b/actions/changeset/check-coverage/test/coverage.bats
@@ -116,6 +116,20 @@ setup() {
   [ "${status}" -eq 0 ]
 }
 
+@test "catalog bump consumed only as a devDependency does not flag the consumer" {
+  # is-string is a runtime dependency of pkg-c but only a devDependency of
+  # pkg-dev. Bumping it must still flag pkg-c (runtime) yet leave pkg-dev
+  # alone — mirrors a block whose build-tool catalog dep (block-tools /
+  # tengo-builder, both devDependencies) bumped without the package itself
+  # being touched. Before the runtime-only scoping this spuriously flagged
+  # pkg-dev.
+  bump_catalog 'is-string' '^1.0.8'
+  run_check
+  [ "${status}" -eq 1 ]
+  [[ "${output}" == *'@check-coverage-test/pkg-c'* ]]
+  [[ "${output}" != *'@check-coverage-test/pkg-dev'* ]]
+}
+
 # ---------------------------------------------------------------------------
 # Empty-changeset corner case.
 # ---------------------------------------------------------------------------
diff --git a/actions/changeset/check-coverage/test/fixtures/minimal-workspace/packages/pkg-dev/index.js b/actions/changeset/check-coverage/test/fixtures/minimal-workspace/packages/pkg-dev/index.js
new file mode 100644
index 00000000..100aff54
--- /dev/null
+++ b/actions/changeset/check-coverage/test/fixtures/minimal-workspace/packages/pkg-dev/index.js
@@ -0,0 +1,3 @@
+// Consumes is-string only as a devDependency (build-tooling stand-in).
+// A catalog bump for is-string must not require this package to be released.
+module.exports = {};
diff --git a/actions/changeset/check-coverage/test/fixtures/minimal-workspace/packages/pkg-dev/package.json b/actions/changeset/check-coverage/test/fixtures/minimal-workspace/packages/pkg-dev/package.json
new file mode 100644
index 00000000..ab988896
--- /dev/null
+++ b/actions/changeset/check-coverage/test/fixtures/minimal-workspace/packages/pkg-dev/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@check-coverage-test/pkg-dev",
+  "version": "1.0.0",
+  "main": "index.js",
+  "devDependencies": {
+    "is-string": "catalog:"
+  }
+}