diff --git a/src/mcp_client.py b/src/mcp_client.py
index 3fa8fca..5950c16 100644
--- a/src/mcp_client.py
+++ b/src/mcp_client.py
@@ -999,10 +999,13 @@ class StdioMCPServer:
   return str(result)
 
 class ExternalMCPManager:
+ """Manages external MCP servers using the StdioMCPServer class."""
  def __init__(self):
+  """Initialize the manager with an empty server registry."""
   self.servers = {}
 
  async def add_server(self, config: models.MCPServerConfig):
+  """Add and start a new MCP server from a configuration object."""
   if config.url:
    # RemoteMCPServer placeholder
    return
@@ -1011,11 +1014,13 @@ class ExternalMCPManager:
   self.servers[config.name] = server
 
  async def stop_all(self):
+  """Stop all managed MCP servers and clear the registry."""
   for server in self.servers.values():
    await server.stop()
   self.servers = {}
 
  def get_all_tools(self) -> dict:
+  """Retrieve a dictionary of all tools available across all managed servers."""
   all_tools = {}
   for sname, server in self.servers.items():
    for tname, tool in server.tools.items():
@@ -1023,9 +1028,11 @@ class ExternalMCPManager:
   return all_tools
 
  def get_servers_status(self) -> dict[str, str]:
+  """Get the current operational status of all managed servers."""
   return {name: server.status for name, server in self.servers.items()}
 
  async def async_dispatch(self, tool_name: str, tool_input: dict) -> str:
+  """Dispatch a tool call to the appropriate external MCP server asynchronously."""
   for server in self.servers.values():
    if tool_name in server.tools:
     return await server.call_tool(tool_name, tool_input)
@@ -1034,11 +1041,10 @@ class ExternalMCPManager:
 _external_mcp_manager = ExternalMCPManager()
 
 def get_external_mcp_manager() -> ExternalMCPManager:
+ """Retrieve the global ExternalMCPManager instance."""
  global _external_mcp_manager
  return _external_mcp_manager
 
-TOOL_NAMES: set[str] = {"read_file", "list_directory", "search_files", "get_file_summary", "py_get_skeleton", "py_get_code_outline", "py_get_definition", "get_git_diff", "web_search", "fetch_url", "get_ui_performance", "get_file_slice", "set_file_slice", "edit_file", "py_update_definition", "py_get_signature", "py_set_signature", "py_get_class_summary", "py_get_var_declaration", "py_set_var_declaration", "py_find_usages", "py_get_imports", "py_check_syntax", "py_get_hierarchy", "py_get_docstring", "get_tree"}
-
 def dispatch(tool_name: str, tool_input: dict[str, Any]) -> str:
  """
     Dispatch an MCP tool call by name.  Returns the result as a string.
@@ -1598,6 +1604,8 @@ MCP_TOOL_SPECS: list[dict[str, Any]] = [
  }
 ]
 
+TOOL_NAMES: set[str] = {t['name'] for t in MCP_TOOL_SPECS}
+
 
 
 
diff --git a/src/shell_runner.py b/src/shell_runner.py
index dd02106..6652a00 100644
--- a/src/shell_runner.py
+++ b/src/shell_runner.py
@@ -1,4 +1,11 @@
 # shell_runner.py
+"""
+Shell Runner - Execution engine for PowerShell scripts.
+
+This module provides utilities to run PowerShell scripts in a subprocess,
+configuring the environment via mcp_env.toml. It handles timeouts,
+logging, and optional QA/patch callbacks for error recovery.
+"""
 import os
 import subprocess
 import shutil
@@ -14,7 +21,7 @@ TIMEOUT_SECONDS: int = 60
 _ENV_CONFIG: dict = {}
 
 def _load_env_config() -> dict:
- """Load mcp_env.toml from project root (sibling of this file or parent dir)."""
+ """Load mcp_env.toml from project root or environment variable."""
  env_path = os.environ.get("SLOP_MCP_ENV")
  if env_path and Path(env_path).exists():
   with open(env_path, "rb") as f:
@@ -30,7 +37,7 @@ def _load_env_config() -> dict:
  return {}
 
 def _build_subprocess_env() -> dict[str, str]:
- """Build env dict for subprocess: current env + mcp_env.toml overrides."""
+ """Build environment dictionary for subprocess with overrides from mcp_env.toml."""
  global _ENV_CONFIG
  if not _ENV_CONFIG:
   _ENV_CONFIG = _load_env_config()