diff --git a/.kiro/specs/three-stage-scan/tasks.md b/.kiro/specs/three-stage-scan/tasks.md
index 681ef1d..d72c30a 100644
--- a/.kiro/specs/three-stage-scan/tasks.md
+++ b/.kiro/specs/three-stage-scan/tasks.md
@@ -4,7 +4,7 @@ This plan ships the three-stage scan without rebuilding CWE policy or the regex
 
 ## Phase 1 — Foundation: Stage contract
 
-- [ ] 1. Introduce the stage plan and mode mapping
+- [x] 1. Introduce the stage plan and mode mapping
 - [x] 1.1 Encode the three stages and the mode-to-stage table
   - Depth `quick` requests only static, `standard` requests static then map, `deep` requests static then map then regress.
   - A skipped stage is a structured reason, not an exception, and can be serialized into the existing degradations list.
@@ -20,7 +20,7 @@ This plan ships the three-stage scan without rebuilding CWE policy or the regex
   - _Boundary: Packaging Configuration_
   - _Depends: 1.1_
 
-- [ ] 1.3 Expand fail-on vocabulary with worth-fixing
+- [x] 1.3 Expand fail-on vocabulary with worth-fixing
   - The scan command accepts `worth-fixing` alongside the existing fail-on values and does not change the meaning of `findings` or `verified`.
   - The existing report exit helper must recognize the new value; unknown values still fail loud.
   - MCP continues to reject `deep` and must not gain docker or shell tools.
@@ -191,3 +191,9 @@ This plan ships the three-stage scan without rebuilding CWE policy or the regex
   - Observable completion: fake-runner tests always run; docker tests skip-or-pass; the default CI workflow still invokes quick-only detection plus the new split-sink map gate.
   - _Requirements: 8.5, 9.1, 9.2_
   - _Depends: 6.3, 7.1_
+
+## Implementation Notes
+
+- `RegressConfig.images` is a sorted tuple of `(language, image)` pairs so frozen config stays hashable.
+- `scan_exit_code` duck-types `worth_fixing` on verdict objects; `_run_scan` still passes no verdicts until task 6.5. Dict-shaped verdicts would not fail the gate.
+- Map `top_k` default is 20 (not named in design.md); `max_hunter_hotspots=8` and `max_candidates=5` follow design.
diff --git a/src/openultrasast/cli.py b/src/openultrasast/cli.py
index bff6996..637d590 100644
--- a/src/openultrasast/cli.py
+++ b/src/openultrasast/cli.py
@@ -69,7 +69,7 @@ def main(argv: list[str] | None = None) -> int:
     scan.add_argument("path", type=Path)
     scan.add_argument("--mode", choices=("quick", "standard", "deep"), default="quick")
     scan.add_argument("--config", type=Path, default=Path("openultrasast.toml"))
-    scan.add_argument("--fail-on", choices=("never", "findings", "verified"), default="never")
+    scan.add_argument("--fail-on", choices=("never", "findings", "verified", "worth-fixing"), default="never")
 
     index = subparsers.add_parser("index", help="chunk a local repository for embedding index construction")
     index.add_argument("path", type=Path)
diff --git a/src/openultrasast/reports.py b/src/openultrasast/reports.py
index 7479b45..1cb6b35 100644
--- a/src/openultrasast/reports.py
+++ b/src/openultrasast/reports.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+from collections.abc import Sequence
 from dataclasses import asdict
 from pathlib import Path
 
@@ -112,13 +113,20 @@ def write_manifest(
     path.write_text(json.dumps(payload, indent=2, sort_keys=True) + "\n")
 
 
-def scan_exit_code(findings: list[StaticFinding], verifications: list[VerificationResult], policy: str) -> int:
+def scan_exit_code(
+    findings: list[StaticFinding],
+    verifications: list[VerificationResult],
+    policy: str,
+    worth_fixing_verdicts: Sequence[object] | None = None,
+) -> int:
     if policy == "never":
         return 0
     if policy == "findings":
         return 1 if findings else 0
     if policy == "verified":
         return 1 if any(result.verified for result in verifications) else 0
+    if policy == "worth-fixing":
+        return 1 if any(getattr(verdict, "worth_fixing", False) for verdict in worth_fixing_verdicts or ()) else 0
     raise ValueError(f"unknown fail policy: {policy}")
 
 
diff --git a/tests/test_mcp.py b/tests/test_mcp.py
index 1573c70..9f8068a 100644
--- a/tests/test_mcp.py
+++ b/tests/test_mcp.py
@@ -54,7 +54,24 @@ def test_surface_exposes_no_shell_or_exec_tool() -> None:
     for name in server.tool_names:
         assert not any(token in name.lower() for token in forbidden), name
     for tool in McpServer()._tools.values():  # no tool accepts a free-form command argument
-        assert "command" not in tool.input_schema.get("properties", {})
+        properties = tool.input_schema.get("properties", {})
+        assert "command" not in properties
+        assert "shell" not in properties
+        assert "docker" not in properties
+
+
+def test_scan_rejects_deep_and_keeps_cli_only_modes() -> None:
+    server = McpServer()
+    listed = server.handle({"jsonrpc": "2.0", "id": 1, "method": "tools/list", "params": {}})
+    assert listed is not None
+    scan_tool = next(tool for tool in listed["result"]["tools"] if tool["name"] == "openultrasast.scan")
+    mode_enum = scan_tool["inputSchema"]["properties"]["mode"]["enum"]
+    assert mode_enum == ["quick", "standard"]
+    assert "deep" not in mode_enum
+
+    result = _call(server, "openultrasast.scan", {"path": ".", "mode": "deep"})
+    assert result["isError"]
+    assert "deep" in result["error"]
 
 
 def test_notifications_get_no_response() -> None:
diff --git a/tests/test_reports.py b/tests/test_reports.py
index b7e0780..cad6e3b 100644
--- a/tests/test_reports.py
+++ b/tests/test_reports.py
@@ -1,5 +1,8 @@
 import json
 from pathlib import Path
+from types import SimpleNamespace
+
+import pytest
 
 from openultrasast.cli import main
 from openultrasast.findings import StaticFinding
@@ -63,11 +66,45 @@ def test_markdown_report_includes_verification_status(tmp_path: Path) -> None:
 def test_scan_exit_code_policy() -> None:
     finding = _finding()
     verification = verify_finding(finding)
+    worth_fixing = SimpleNamespace(worth_fixing=True)
 
     assert scan_exit_code([finding], [verification], "never") == 0
     assert scan_exit_code([finding], [verification], "findings") == 1
+    assert scan_exit_code([], [], "findings") == 0
     assert scan_exit_code([finding], [verification], "verified") == 1
     assert scan_exit_code([], [], "verified") == 0
+    # findings/verified ignore worth-fixing verdicts
+    assert scan_exit_code([], [], "findings", worth_fixing_verdicts=[worth_fixing]) == 0
+    assert scan_exit_code([], [], "verified", worth_fixing_verdicts=[worth_fixing]) == 0
+    assert scan_exit_code([finding], [verification], "findings", worth_fixing_verdicts=[worth_fixing]) == 1
+    assert scan_exit_code([finding], [verification], "verified", worth_fixing_verdicts=[worth_fixing]) == 1
+
+
+def test_scan_exit_code_worth_fixing() -> None:
+    finding = _finding()
+    verification = verify_finding(finding)
+    worth_fixing = SimpleNamespace(worth_fixing=True)
+    not_worth_fixing = SimpleNamespace(worth_fixing=False)
+
+    assert scan_exit_code([finding], [verification], "worth-fixing") == 0
+    assert scan_exit_code([finding], [verification], "worth-fixing", worth_fixing_verdicts=[]) == 0
+    assert scan_exit_code([finding], [verification], "worth-fixing", worth_fixing_verdicts=[not_worth_fixing]) == 0
+    assert scan_exit_code([finding], [verification], "worth-fixing", worth_fixing_verdicts=[worth_fixing]) == 1
+
+
+def test_scan_exit_code_unknown_policy() -> None:
+    with pytest.raises(ValueError, match="unknown fail policy"):
+        scan_exit_code([], [], "maybe")
+
+
+def test_scan_help_lists_worth_fixing(capsys: pytest.CaptureFixture[str]) -> None:
+    with pytest.raises(SystemExit) as exc:
+        main(["scan", "--help"])
+    assert exc.value.code == 0
+    help_text = capsys.readouterr().out
+    assert "worth-fixing" in help_text
+    assert "findings" in help_text
+    assert "verified" in help_text
 
 
 def test_cli_scan_writes_sarif_manifest_and_honors_fail_policy(tmp_path: Path, monkeypatch) -> None:  # type: ignore[no-untyped-def]
@@ -87,6 +124,15 @@ def test_cli_scan_writes_sarif_manifest_and_honors_fail_policy(tmp_path: Path, m
     assert manifest["findings"][0]["artifact_refs"]["verification_json"] == "verification.json"
 
 
+def test_cli_scan_fail_on_worth_fixing_exits_zero_without_verdicts(tmp_path: Path, monkeypatch) -> None:  # type: ignore[no-untyped-def]
+    repo = tmp_path / "repo"
+    repo.mkdir()
+    (repo / "app.py").write_text("@app.route('/admin')\ndef admin():\n    return eval(request.data)\n")
+    monkeypatch.setenv("OPENULTRASAST_RUNS_DIR", ".runs")
+
+    assert main(["scan", str(repo), "--mode", "quick", "--fail-on", "worth-fixing"]) == 0
+
+
 def _finding() -> StaticFinding:
     return StaticFinding(
         finding_id="python-unsafe-eval:app.py:3",