diff --git a/scripts/resolvers/preamble.ts b/scripts/resolvers/preamble.ts
index 3654438cc..07183bdcb 100644
--- a/scripts/resolvers/preamble.ts
+++ b/scripts/resolvers/preamble.ts
@@ -2,11 +2,15 @@
  * Preamble composition root.
  *
  * Each generator lives in its own file under ./preamble/*.ts. This file only
- * wires them together via generatePreamble(). Keep composition declarative —
- * no inline logic beyond tier gating.
+ * wires them together: preambleSections() is the composition, and
+ * generatePreamble() joins it into the full inline render (tier 1 skills and
+ * the tests' oracle). For tier 2+ skills, {{PREAMBLE}} resolves through
+ * ./preamble-hoist.ts, which splits the same sections into a per-skill pointer
+ * plus the shared sections/preamble.md the skill Reads on load. Keep
+ * composition declarative — no inline logic beyond tier gating.
  *
  * Each skill runs independently via `claude -p` (or the host's equivalent).
- * There is no shared loader. The preamble provides: update checks, session
+ * The preamble provides: update checks, session
  * tracking, user preferences, repo mode detection, model overlays, and
  * telemetry.
  *
diff --git a/test/gen-skill-docs.test.ts b/test/gen-skill-docs.test.ts
index 1e0e9db44..057bafe32 100644
--- a/test/gen-skill-docs.test.ts
+++ b/test/gen-skill-docs.test.ts
@@ -3131,9 +3131,10 @@ describe('Codex generation (--host codex)', () => {
     // Verify across ALL generated skills, not just review
     for (const skill of CODEX_SKILLS) {
       const content = fs.readFileSync(path.join(AGENTS_DIR, skill.codexName, 'SKILL.md'), 'utf-8');
-      // No skill should reference Claude paths
-      expect(content).not.toContain('~/.claude/skills');
-      expect(content).not.toContain('.claude/skills');
+      // No skill should reference Claude paths, including in its shared sections/preamble.md
+      const startup = readSkillStartup(path.join(AGENTS_DIR, skill.codexName, 'SKILL.md'));
+      expect(startup).not.toContain('~/.claude/skills');
+      expect(startup).not.toContain('.claude/skills');
       if (content.includes('gstack-config') || content.includes('gstack-update-check') || content.includes('gstack-telemetry-log')) {
         expect(content).toContain('$GSTACK_ROOT');
       }
@@ -3335,14 +3336,14 @@ describe('Factory generation (--host factory)', () => {
 
   test('no .claude/skills/ in Factory output', () => {
     for (const skill of FACTORY_SKILLS) {
-      const content = fs.readFileSync(path.join(FACTORY_DIR, skill.factoryName, 'SKILL.md'), 'utf-8');
+      const content = readSkillStartup(path.join(FACTORY_DIR, skill.factoryName, 'SKILL.md'));
       expect(content).not.toContain('.claude/skills');
     }
   });
 
   test('no ~/.claude/skills/ paths in Factory output', () => {
     for (const skill of FACTORY_SKILLS) {
-      const content = fs.readFileSync(path.join(FACTORY_DIR, skill.factoryName, 'SKILL.md'), 'utf-8');
+      const content = readSkillStartup(path.join(FACTORY_DIR, skill.factoryName, 'SKILL.md'));
       // ~/.claude/skills should be rewritten, but ~/.claude/plans is legitimate
       // (plan directory lookup) and ~/.claude/ in codex prompts is intentional
       expect(content).not.toContain('~/.claude/skills');
diff --git a/test/host-config.test.ts b/test/host-config.test.ts
index 4a66af701..a7155b8bb 100644
--- a/test/host-config.test.ts
+++ b/test/host-config.test.ts
@@ -29,6 +29,7 @@ import { HOST_PATHS } from '../scripts/resolvers/types';
 import { RESOLVERS } from '../scripts/resolvers';
 import { expectTokens } from './helpers/prompt-structure';
 import { runGeneration } from '../scripts/gen-skill-docs';
+import { readSkillStartup } from './helpers/skill-startup';
 
 const ROOT = path.resolve(import.meta.dir, '..');
 const RESOLVER_NAMES = new Set(Object.keys(RESOLVERS));
@@ -746,7 +747,7 @@ describe('Copilot host render (#393)', () => {
 
   test('paths name the Copilot install, never Claude or Codex', () => {
     for (const skill of ['gstack-review', 'gstack-ship', 'gstack-careful', 'gstack-upgrade']) {
-      const md = read(skill);
+      const md = readSkillStartup(path.join(OUT, '.copilot', 'skills', skill, 'SKILL.md'));
       expect(md).not.toContain('~/.claude/skills/gstack');
       expect(md).not.toContain('$HOME/.claude/skills/gstack');
       expect(md).not.toContain('.codex/skills');
@@ -779,7 +780,7 @@ describe('Antigravity CLI host render', () => {
 
   test('paths name the Antigravity CLI install, never Claude, Codex or Gemini CLI skill dirs', () => {
     for (const skill of ['gstack-review', 'gstack-ship', 'gstack-careful', 'gstack-upgrade']) {
-      const md = read(skill);
+      const md = readSkillStartup(path.join(dir, skill, 'SKILL.md'));
       expect(md).not.toContain('~/.claude/skills/gstack');
       expect(md).not.toContain('$HOME/.claude/skills/gstack');
       expect(md).not.toContain('.codex/skills');
diff --git a/test/host-conformance.test.ts b/test/host-conformance.test.ts
index 6b8de314e..38dc5c966 100644
--- a/test/host-conformance.test.ts
+++ b/test/host-conformance.test.ts
@@ -16,7 +16,7 @@ import { join } from 'node:path';
 import { ALL_HOST_CONFIGS } from '../hosts/index';
 import { cleanupFixtures, cleanupSeed, makeFixture, makeSource, put, registryRows, runSetup, setVersion, tree } from './helpers/install-fixture';
 import { expectTokens } from './helpers/prompt-structure';
-import { readSkillStartup } from './helpers/skill-startup';
+import { readSkillStartup, SHARED_PREAMBLE_FILE } from './helpers/skill-startup';
 
 afterEach(cleanupFixtures);
 afterAll(cleanupSeed);
@@ -81,7 +81,7 @@ function brokenSectionPointers(dest: string, runtimeRoot: string, home: string):
         let targets: string[];
         if (tok.startsWith('sections/')) {
           if (names.length) targets = names.map(n => join(dest, n, tok));
-          else if ((existsSync(join(dir, 'sections')) && readdirSync(join(dir, 'sections'), { withFileTypes: true }).some(e => e.name.endsWith('.md') && e.name !== 'preamble.md')) || stop) targets = [join(dir, tok)];
+          else if ((existsSync(join(dir, 'sections')) && readdirSync(join(dir, 'sections'), { withFileTypes: true }).some(e => e.name.endsWith('.md') && e.name !== SHARED_PREAMBLE_FILE)) || stop) targets = [join(dir, tok)];
           else continue;
         } else if (tok.startsWith('$GSTACK_ROOT/')) targets = [join(runtimeRoot, tok.slice('$GSTACK_ROOT/'.length))];
         else if (tok.startsWith('~/')) targets = [join(home, tok.slice(2))];
diff --git a/test/workflow-judge-input.test.ts b/test/workflow-judge-input.test.ts
index 8ae458757..ee3c751b5 100644
--- a/test/workflow-judge-input.test.ts
+++ b/test/workflow-judge-input.test.ts
@@ -6,7 +6,7 @@ import { dirname, join, resolve } from 'node:path';
 import { createHash } from 'node:crypto';
 import { readWorkflowJudgeInput, buildWorkflowJudgePrompt, QA_DISCOVERY_REFERENCES, WORKFLOW_JUDGE_RESPONSE_SCHEMA, WORKFLOW_JUDGE_REASONING_WORD_LIMIT } from './helpers/workflow-judge-input';
 import { ASK_QUESTIONS_HEADING, ENG_REVIEW_EXCERPT } from './helpers/workflow-excerpt';
-import { readSkillStartup } from './helpers/skill-startup';
+import { readSkillStartup, SHARED_PREAMBLE_FILE } from './helpers/skill-startup';
 
 const ROOT = resolve(import.meta.dir, '..');
 const scratchRoots: string[] = [];
@@ -79,7 +79,7 @@ function sectionPaths(skill: string): string[] {
   const runnerOnly = new Set((JSON.parse(readFileSync(join(ROOT, skill, 'sections', 'manifest.json'), 'utf8')).sections as Array<{ file: string; runner_only?: boolean }>)
     .filter(section => section.runner_only).map(section => section.file));
   return readdirSync(join(ROOT, skill, 'sections'))
-    .filter(name => name.endsWith('.md') && !runnerOnly.has(name) && name !== 'preamble.md')
+    .filter(name => name.endsWith('.md') && !runnerOnly.has(name) && name !== SHARED_PREAMBLE_FILE)
     .sort()
     .map(name => `${skill}/sections/${name}`);
 }