Add admin-only BookStack MCP connector

Load an allowlisted subset of bookstack-mcp tools (search/read plus
create/update books, chapters, pages and comments; no deletes) over stdio
and add them to the admin agent alongside Homebox. Extract the shared
allowlist + is_admin wrapping into utils/mcp_tools.py.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

utils/homebox_mcp.py

@@ -7,9 +7,10 @@ re-checks ``is_admin`` in the run config as a second line of defense.
 import logging
 import os
 
-from langchain_core.runnables import RunnableConfig
 from langchain_core.tools import BaseTool, StructuredTool
 
+from utils.mcp_tools import admin_only_message, load_stdio_tools, select_tools
+
 logger = logging.getLogger(__name__)
 
 # Read + safe writes only. The server exposes ~39 tools; exposing all of them
@@ -28,65 +29,13 @@ HOMEBOX_TOOL_ALLOWLIST = (
     "log_maintenance",
 )
 
-DESCRIPTION_MAX_CHARS = 300
-ADMIN_ONLY_MESSAGE = "Homebox access is restricted to admin users."
-
-
-def _content_to_text(content) -> str:
-    """Flatten MCP content blocks into plain text for the LLM and persistence."""
-    if isinstance(content, str):
-        return content
-    if isinstance(content, (list, tuple)):
-        parts = []
-        for block in content:
-            if isinstance(block, dict):
-                parts.append(block.get("text") or f"[{block.get('type', 'content')}]")
-            else:
-                parts.append(str(block))
-        return "\n".join(parts)
-    return str(content)
-
-
-def _short_description(description: str) -> str:
-    description = " ".join((description or "").split())
-    if len(description) > DESCRIPTION_MAX_CHARS:
-        description = description[: DESCRIPTION_MAX_CHARS - 3].rstrip() + "..."
-    return description
-
-
-def wrap_admin_only(inner: BaseTool) -> StructuredTool:
-    """Rename an MCP tool to ``homebox_<name>`` and gate it on ``is_admin``."""
-
-    async def call(config: RunnableConfig, **kwargs) -> str:
-        if not (config or {}).get("configurable", {}).get("is_admin"):
-            return ADMIN_ONLY_MESSAGE
-        try:
-            result = await inner.coroutine(**kwargs)
-        except Exception as e:
-            return f"Homebox error: {e}"
-        content = result[0] if isinstance(result, tuple) else result
-        return _content_to_text(content)
-
-    return StructuredTool(
-        name=f"homebox_{inner.name}",
-        description=_short_description(inner.description),
-        args_schema=inner.args_schema,
-        coroutine=call,
-        metadata=inner.metadata,
-    )
+LABEL = "Homebox"
+ADMIN_ONLY_MESSAGE = admin_only_message(LABEL)
 
 
 def select_homebox_tools(mcp_tools: list[BaseTool]) -> list[StructuredTool]:
     """Keep allowlisted tools (in allowlist order) and wrap them admin-only."""
-    by_name = {t.name: t for t in mcp_tools}
-    missing = [name for name in HOMEBOX_TOOL_ALLOWLIST if name not in by_name]
-    if missing:
-        logger.warning(f"Homebox MCP: server is missing tools {missing}")
-    return [
-        wrap_admin_only(by_name[name])
-        for name in HOMEBOX_TOOL_ALLOWLIST
-        if name in by_name
-    ]
+    return select_tools(mcp_tools, HOMEBOX_TOOL_ALLOWLIST, "homebox", LABEL)
 
 
 async def load_homebox_tools() -> list[StructuredTool]:
@@ -97,27 +46,11 @@ async def load_homebox_tools() -> list[StructuredTool]:
         logger.info("Homebox MCP not configured (HOMEBOX_URL/HOMEBOX_TOKEN unset)")
         return []
 
-    try:
-        from langchain_mcp_adapters.client import MultiServerMCPClient
-
-        client = MultiServerMCPClient(
-            {
-                "homebox": {
-                    "transport": "stdio",
-                    "command": os.getenv("HOMEBOX_MCP_COMMAND", "homebox-mcp"),
-                    "args": [],
-                    "env": {
-                        "HOMEBOX_URL": url,
-                        "HOMEBOX_TOKEN": token,
-                        "PATH": os.environ.get("PATH", ""),
-                    },
-                }
-            }
-        )
-        tools = select_homebox_tools(await client.get_tools())
-    except Exception:
-        logger.exception("Homebox MCP failed to load; continuing without it")
-        return []
-
-    logger.info(f"Homebox MCP: loaded {len(tools)} tools")
-    return tools
+    return await load_stdio_tools(
+        server="homebox",
+        command=os.getenv("HOMEBOX_MCP_COMMAND", "homebox-mcp"),
+        env={"HOMEBOX_URL": url, "HOMEBOX_TOKEN": token},
+        allowlist=HOMEBOX_TOOL_ALLOWLIST,
+        prefix="homebox",
+        label=LABEL,
+    )