diff --git a/setup b/setup
index f812511e4..1dc085fc7 100755
--- a/setup
+++ b/setup
@@ -402,6 +402,28 @@ link_claude_skill_dirs() {
       # Validate target isn't a symlink before creating the link
       if [ -L "$target/SKILL.md" ]; then rm "$target/SKILL.md"; fi
       ln -snf "$gstack_dir/$dir_name/SKILL.md" "$target/SKILL.md"
+      # Symlink supporting .md files so SKILL.md can read them via .claude/skills/<skill>/
+      # path (checklist.md, greptile-triage.md, design-checklist.md, TODOS-format.md, etc.)
+      # Excludes SKILL.md (already linked above) and *.tmpl template sources.
+      for support_file in "$gstack_dir/$dir_name"/*.md; do
+        [ -f "$support_file" ] || continue
+        fname="$(basename "$support_file")"
+        [ "$fname" = "SKILL.md" ] && continue
+        if [ -L "$target/$fname" ]; then rm "$target/$fname"; fi
+        ln -snf "$support_file" "$target/$fname"
+      done
+      # Symlink support asset directories (specialists/, references/, templates/, bin/, etc.)
+      # Excludes build and source dirs: dist, src, test, tests, scripts, node_modules.
+      for support_dir in "$gstack_dir/$dir_name"/*/; do
+        [ -d "$support_dir" ] || continue
+        sname="$(basename "$support_dir")"
+        case "$sname" in
+          dist|src|test|tests|scripts|node_modules) continue ;;
+        esac
+        if [ -L "$target/$sname" ]; then rm "$target/$sname"; fi
+        if [ -e "$target/$sname" ] && [ ! -L "$target/$sname" ]; then rm -rf "$target/$sname"; fi
+        ln -snf "$gstack_dir/$dir_name/$sname" "$target/$sname"
+      done
       linked+=("$link_name")
     fi
   done
diff --git a/test/gen-skill-docs.test.ts b/test/gen-skill-docs.test.ts
index 4bf8abeee..789e38a05 100644
--- a/test/gen-skill-docs.test.ts
+++ b/test/gen-skill-docs.test.ts
@@ -2270,6 +2270,33 @@ describe('setup script validation', () => {
     expect(fnBody).toContain('rm -f "$target"');
   });
 
+  // FIX #1499: link function must also mirror supporting .md files and asset directories
+  // so SKILL.md Step 2 can read checklist.md, greptile-triage.md, specialists/, etc.
+  // via .claude/skills/<skill>/<file> without requiring gstack-prefixed paths.
+  test('link_claude_skill_dirs symlinks supporting .md files alongside SKILL.md', () => {
+    const fnStart = setupContent.indexOf('link_claude_skill_dirs()');
+    const fnEnd = setupContent.indexOf('}', setupContent.indexOf('linked[@]}', fnStart));
+    const fnBody = setupContent.slice(fnStart, fnEnd);
+    // Must iterate over sibling .md files in the skill source dir
+    expect(fnBody).toContain('for support_file in "$gstack_dir/$dir_name"/*.md');
+    // Must skip SKILL.md itself (already linked above)
+    expect(fnBody).toContain('[ "$fname" = "SKILL.md" ] && continue');
+    // Must create symlinks for each support file
+    expect(fnBody).toContain('ln -snf "$support_file" "$target/$fname"');
+  });
+
+  test('link_claude_skill_dirs symlinks support asset directories (specialists/, bin/, etc.)', () => {
+    const fnStart = setupContent.indexOf('link_claude_skill_dirs()');
+    const fnEnd = setupContent.indexOf('}', setupContent.indexOf('linked[@]}', fnStart));
+    const fnBody = setupContent.slice(fnStart, fnEnd);
+    // Must iterate over subdirectories in the skill source dir
+    expect(fnBody).toContain('for support_dir in "$gstack_dir/$dir_name"/*/');
+    // Must exclude build and source dirs to avoid polluting the skill surface
+    expect(fnBody).toContain('dist|src|test|tests|scripts|node_modules');
+    // Must create symlinks for qualifying support dirs
+    expect(fnBody).toContain('ln -snf "$gstack_dir/$dir_name/$sname" "$target/$sname"');
+  });
+
   test('setup supports --host auto|claude|codex|kiro|opencode', () => {
     expect(setupContent).toContain('--host');
     expect(setupContent).toContain('claude|codex|kiro|factory|opencode|auto');