diff --git a/src/resources/extensions/gsd/codebase-generator.ts b/src/resources/extensions/gsd/codebase-generator.ts
index f56d84079..b291c3c1f 100644
--- a/src/resources/extensions/gsd/codebase-generator.ts
+++ b/src/resources/extensions/gsd/codebase-generator.ts
@@ -71,13 +71,23 @@ interface EnumeratedFiles {
 // ─── Defaults ────────────────────────────────────────────────────────────────
 
 const DEFAULT_EXCLUDES = [
+  // ── AI / tooling meta ──
+  ".agents/",
   ".gsd/",
   ".planning/",
   ".plans/",
   ".claude/",
   ".cursor/",
+  ".bg-shell/",
+
+  // ── Editor / IDE ──
   ".vscode/",
+  ".idea/",
+
+  // ── VCS ──
   ".git/",
+
+  // ── Dependencies & build artifacts ──
   "node_modules/",
   "dist/",
   "build/",
@@ -85,7 +95,13 @@ const DEFAULT_EXCLUDES = [
   "coverage/",
   "__pycache__/",
   ".venv/",
+  "venv/",
   "vendor/",
+  "target/",
+
+  // ── Misc ──
+  ".cache/",
+  "tmp/",
 ];
 
 const DEFAULT_MAX_FILES = 500;
diff --git a/src/resources/extensions/gsd/tests/codebase-generator.test.ts b/src/resources/extensions/gsd/tests/codebase-generator.test.ts
index d8d3d74c8..923c19f1d 100644
--- a/src/resources/extensions/gsd/tests/codebase-generator.test.ts
+++ b/src/resources/extensions/gsd/tests/codebase-generator.test.ts
@@ -162,6 +162,34 @@ test("generateCodebaseMap: excludes .claude/ and other tool directories", () =>
   }
 });
 
+test("generateCodebaseMap: excludes .agents/ and other tooling directories", () => {
+  const base = makeTmpRepo();
+  try {
+    addFile(base, "src/main.ts");
+    addFile(base, ".agents/skills/pdf/SKILL.md");
+    addFile(base, ".agents/skills/find-skills/SKILL.md");
+    addFile(base, ".bg-shell/session.json");
+    addFile(base, ".idea/workspace.xml");
+    addFile(base, ".cache/data.bin");
+    addFile(base, "tmp/scratch.ts");
+    addFile(base, "target/debug/build.rs");
+    addFile(base, "venv/lib/site.py");
+
+    const result = generateCodebaseMap(base);
+    assert.ok(result.content.includes("`src/main.ts`"), "should include src/main.ts");
+    assert.ok(!result.content.includes("SKILL.md"), "should exclude .agents/ files");
+    assert.ok(!result.content.includes(".bg-shell"), "should exclude .bg-shell/ files");
+    assert.ok(!result.content.includes(".idea"), "should exclude .idea/ files");
+    assert.ok(!result.content.includes(".cache"), "should exclude .cache/ files");
+    assert.ok(!result.content.includes("tmp/"), "should exclude tmp/ files");
+    assert.ok(!result.content.includes("target"), "should exclude target/ files");
+    assert.ok(!result.content.includes("venv"), "should exclude venv/ files");
+    assert.equal(result.fileCount, 1);
+  } finally {
+    cleanup(base);
+  }
+});
+
 test("generateCodebaseMap: excludes binary and lock files", () => {
   const base = makeTmpRepo();
   try {