cursor-before-mcp-execution-guard

hook BeforeMCPExecution cursor mode: enforce

Block destructive MCP tool calls (shell passthroughs, out-of-workspace deletes) before execution in Cursor.

Registry Entry

Field	Value
id	cursor-before-mcp-execution-guard
status_message	Checking MCP-execution safety
mode	enforce
logical_event	BeforeMCPExecution
command	python3 {repo_root}/hooks/wagents-hook.py cursor-before-mcp-execution-guard --harness {harness}
timeout	5
harnesses	["cursor"]

Note

Maps to Cursor’s native beforeMCPExecution event. Decision logic in wagents/hooks/policies/before_mcp_execution.py (evaluate_before_mcp_execution) inspects the tool name + params for dangerous shell passthroughs and absolute/traversal delete paths. Invoked by _policy_cursor_before_mcp_execution_guard; fail-closed.

Full hook config + policy reference

config/hook-registry.json (entry)

{
  "id": "cursor-before-mcp-execution-guard",
  "description": "Block destructive MCP tool calls (shell passthroughs, out-of-workspace deletes) before execution in Cursor.",
  "status_message": "Checking MCP-execution safety",
  "mode": "enforce",
  "logical_event": "BeforeMCPExecution",
  "command": "python3 {repo_root}/hooks/wagents-hook.py cursor-before-mcp-execution-guard --harness {harness}",
  "timeout": 5,
  "harnesses": [
    "cursor"
  ]
}

wagents/hooks/policies/before_mcp_execution.py (decision)

def evaluate_before_mcp_execution(tool_name: str, params: dict[str, Any] | None) -> str | None:
    """Return a deny reason for dangerous MCP calls, else None."""
    # Blocks destructive commands passed through MCP shell tools and
    # absolute / path-traversal deletes that escape the workspace.
    ...

Command: python3 .../wagents-hook.py cursor-before-mcp-execution-guard --harness cursor

Resources

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