fix(mcp): the default mode disabled the unified hanzo tool

0.15.13 shipped the 166-service surface switched off. `tools/list` against a
clean install returned 40 tools with no `hanzo`, and the server logged
"unified `hanzo` tool unavailable — keeping per-service tools enabled".

The import was fine; the mode gate was not. register_all_tools() asks
is_tool_enabled("hanzo", True), which returns tool_config["hanzo"] whenever the
key exists rather than falling back to the default. ModeLoader builds that
config by disabling every TOOL_REGISTRY key and re-enabling only the active
mode's tools. TOOL_REGISTRY has "hanzo"; the default personality's list did
not — so the "True" default was never reached and the tool was explicitly off.

Two things broke together, because the per-service cloud tools are retired only
once `hanzo` is enabled: the unified surface was absent AND the ten tools it
replaces were still mounted. The exact state 929e103e set out to end.

`hanzo` belongs in ESSENTIAL_TOOLS. It is an axis like fs or git — the single
seam to the platform — not a mode-specific extra. It stays out of
ESSENTIAL_SYSTEM_TOOLS so it remains disableable.

Verified in a clean uv venv from built wheels only (no editable, no PYTHONPATH):
tools/list now returns 31 tools including `hanzo`, and api/auth/billing/commerce/
iam/ingress/kms/mpc/paas/team are correctly gone (40 - 10 + 1). The tool answers
hanzo(service="services") with 166 services read live from
https://api.hanzo.ai/v1/openapi.json.

A test now pins the gate where it is actually decided. It fails against the
installed 0.15.13 (3 of 4) and passes against 0.15.14 — an import-level check
cannot catch this, because the import succeeds.

Co-authored-by: Hanzo Dev <[email protected]>

pkg/hanzo-mcp/hanzo_mcp/tools/common/personality.py

@@ -116,6 +116,12 @@ ESSENTIAL_TOOLS = [
     "critic",
     # Agent spawning
     "agent",
+    # Hanzo cloud — one tool projecting every service from the OpenAPI registry.
+    # It is an axis like the rest: the single seam to the platform, and the tool
+    # the per-service cloud tools are retired in favour of. A mode omitting it
+    # does not merely lose `hanzo`, it un-retires those ten legacy tools, because
+    # register_all_tools() only hides them once `hanzo` is enabled.
+    "hanzo",
     # System / configuration
     "config",
     "mode",

pkg/hanzo-mcp/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "hanzo-mcp"
-version = "0.15.13"
+version = "0.15.14"
 description = "The Zen of Hanzo MCP: One server to rule them all. The ultimate MCP that orchestrates all others."
 readme = "README.md"
 requires-python = ">=3.12"

pkg/hanzo-mcp/tests/test_unified_hanzo_enabled.py

@@ -0,0 +1,81 @@
+"""Regression: the default mode must leave the unified `hanzo` tool enabled.
+
+The bug this guards against: ``register_all_tools`` gates the unified tool on
+``is_tool_enabled("hanzo", True)``, which returns ``tool_config["hanzo"]``
+whenever that key exists. ``ModeLoader.get_enabled_tools_from_mode`` builds
+``tool_config`` by disabling every key in ``TOOL_REGISTRY`` and then re-enabling
+only the active mode's ``tools`` list. ``TOOL_REGISTRY`` has ``"hanzo"``, so a
+mode that omits it does not fall back to the ``True`` default — it explicitly
+disables it.
+
+That is what shipped in 0.15.13: the tool built, imported, and registered its
+entry point, yet ``tools/list`` came back with 40 tools and no ``hanzo``, while
+the server logged "unified `hanzo` tool unavailable". Two things broke at once,
+because ``register_all_tools`` only retires the per-service cloud tools once
+``hanzo`` is enabled — so the 166-service surface was off AND the ten tools it
+replaces were still on. An import-level check cannot catch this: the import
+succeeds. The gate has to be tested where it is actually decided.
+"""
+
+import pytest
+
+from hanzo_mcp.config.tool_config import TOOL_REGISTRY
+from hanzo_mcp.tools import SUPERSEDED_BY_HANZO, _unified_hanzo_available
+from hanzo_mcp.tools.common.mode import ModeRegistry, activate_mode_from_env
+from hanzo_mcp.tools.common.mode_loader import ModeLoader
+
+UNIFIED = "hanzo"
+
+
+@pytest.fixture(autouse=True)
+def _modes_loaded():
+    """Modes are registered lazily; the gate reads whatever is active."""
+    ModeLoader.initialize_modes()
+    activate_mode_from_env()
+
+
+def test_unified_tool_is_in_the_registry():
+    """If it left TOOL_REGISTRY the clean-slate loop could no longer reach it."""
+    assert UNIFIED in TOOL_REGISTRY
+
+
+def test_default_mode_lists_the_unified_tool():
+    """The active mode must name `hanzo`, or the clean slate leaves it off."""
+    mode = ModeRegistry.get_active()
+    assert mode is not None, "no active mode; the gate would read an empty config"
+    assert UNIFIED in mode.tools, (
+        f"mode {mode.name!r} omits {UNIFIED!r}, so ModeLoader disables it. "
+        f"mode.tools={sorted(mode.tools)}"
+    )
+
+
+def test_resolved_config_enables_the_unified_tool():
+    """The fingerprint of the 0.15.13 regression: tool_config['hanzo'] is False."""
+    config = ModeLoader.get_enabled_tools_from_mode(
+        base_enabled_tools=None, force_mode=None
+    )
+    assert config.get(UNIFIED) is True, (
+        f"tool_config[{UNIFIED!r}]={config.get(UNIFIED)!r} — register_all_tools "
+        "will skip the unified tool and keep the per-service tools it replaces."
+    )
+
+
+def test_superseded_tools_are_retired_when_the_unified_tool_is_available():
+    """Enabling `hanzo` is what retires the ten per-service cloud tools.
+
+    Mirrors the branch in register_all_tools so the two cannot drift: if the
+    unified tool imports and the mode enables it, none of the tools it replaces
+    should survive into the resolved config.
+    """
+    if not _unified_hanzo_available():
+        pytest.skip("hanzo-tools-api not installed; nothing to supersede")
+
+    config = ModeLoader.get_enabled_tools_from_mode(
+        base_enabled_tools=None, force_mode=None
+    )
+    assert config.get(UNIFIED) is True
+
+    still_on = [t for t in SUPERSEDED_BY_HANZO if config.get(t)]
+    assert not still_on, (
+        f"{still_on} stayed enabled alongside the unified tool that replaces them"
+    )