ci: skip the PR description check for Dependabot

.github/workflows/pr-description-check.yml

@@ -10,6 +10,8 @@ permissions:
 
 jobs:
   check-pr-description:
+    # Dependabot writes its own body with none of these headings, so its PRs could never pass; the author decides, not the actor.
+    if: github.event.pull_request.user.login != 'dependabot[bot]'
     runs-on: ubuntu-latest
     steps:
       - name: Check required sections

AGENTS.md

@@ -271,6 +271,8 @@ test(tools): add registry conflict detection
 
 ### PR Description Template
 
+CI's `check-pr-description` job requires `## Why`, `## What Changed` and `## Testing`. It skips a pull request Dependabot opened, since Dependabot writes its own body.
+
 ```markdown
 ## Why
 

scripts/pr-description-check.test.ts

@@ -0,0 +1,47 @@
+import {spawnSync} from 'node:child_process';
+import {readFileSync} from 'node:fs';
+import {join} from 'node:path';
+import {parseDocument} from 'yaml';
+import {root} from './lib/repo-root.mjs';
+
+type Job = {if?: string; steps: {run: string; if?: string}[]};
+
+const job = (): Job => {
+  const workflow = parseDocument(readFileSync(join(root, '.github/workflows/pr-description-check.yml'), 'utf8')).toJS();
+
+  return (workflow as {jobs: Record<string, Job>}).jobs['check-pr-description'];
+};
+
+const checkBody = (body: string) => {
+  const [step] = job().steps;
+  const {status, stdout} = spawnSync('bash', ['-c', step.run], {
+    encoding: 'utf8',
+    env: {...process.env, PR_BODY: body},
+  });
+
+  return {status, stdout};
+};
+
+describe('the pull request description check', () => {
+  it('skips a pull request Dependabot opened, by its author rather than whoever edits it', () => {
+    expect({condition: job().if, stepConditions: job().steps.map(step => 'if' in step)}).toEqual({
+      condition: "github.event.pull_request.user.login != 'dependabot[bot]'",
+      stepConditions: [false],
+    });
+  });
+
+  it('still passes a body with all three headings and fails a Dependabot-style one, naming each it lacks', () => {
+    expect({
+      complete: checkBody('## Why\n\nA.\n\n## What Changed\n\nB.\n\n## Testing\n\nC.\n'),
+      dependabotStyle: checkBody('Bumps [@types/node](https://github.com/DefinitelyTyped) from 26.6.5 to 26.6.6.\n'),
+    }).toEqual({
+      complete: {status: 0, stdout: 'All required PR description sections are present.\n'},
+      dependabotStyle: {
+        status: 1,
+        stdout:
+          '::error::PR description is missing required sections: ## Why ## What Changed ## Testing\n' +
+          'Required sections: ## Why, ## What Changed, ## Testing\n',
+      },
+    });
+  });
+});

specs/hal-engine-doc-gates/spec.md

@@ -61,6 +61,13 @@ Spike documents are covered differently. A spike records what was believed when
 
 Two steps of that job are deliberately outside the script: the spec anchor check and the changelog check both diff against `origin/main`, and neither behaves the same on a checkout as it does against a pull request's base.
 
+## The pull request description check leaves Dependabot alone
+
+`pr-description-check.yml` asks for three headings that Dependabot's body never has, so every Dependabot pull request showed a red check nothing could turn green.
+
+- The check skips a pull request Dependabot opened, decided by its author rather than by whoever edits it ([validated by: skips a pull request Dependabot opened, by its author rather than whoever edits it](../../scripts/pr-description-check.test.ts#L26)).
+- It still fails any other body that lacks a heading, naming each one ([validated by: still passes a body with all three headings and fails a Dependabot-style one, naming each it lacks](../../scripts/pr-description-check.test.ts#L33)).
+
 ## Paths in prose resolve
 
 `npm run docs:check-paths` resolves every backticked repository path written in a document - `src/`, `scripts/`, `example/`, `smoke/`, `docs/`, `specs/`, `adrs/`, `dist/`, `.github/` and `.specify/`. A path that legitimately does not resolve is named in the script's own allowlist with the reason, because an exception has to be written down to be one; narrowing the pattern instead would hide every other path behind the same prefix. A path in prose is a citation, and a citation nobody resolves rots in silence: the file moves, the sentence naming it stays, and the next reader follows it to nothing.