AI agents call delete_custom_property to permanently remove resources in Docx — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
The tool performs an irreversible deletion operation on document properties. Once deleted, custom properties cannot be recovered through standard undo mechanisms within the document context. Although the blast radius is limited to document metadata rather than main content, deletion operations are categorized as Destructive per the classification rules.
From the tool's definition Tool name contains 'delete' and description states 'Delete a custom document property by name' — this irreversibly removes metadata from a Word document.
Documented attack patterns abuse exactly the kind of access delete_custom_property gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Docx, and nothing reaches the server without passing your rules. This is the rule we recommend for delete_custom_property:
{
"version": "1",
"default": "deny",
"hide": [
"delete_custom_property"
]
}delete_custom_property disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.
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Delete a custom document property by name. It is categorised as a Destructive tool in the Docx MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Docx MCP server in PolicyLayer and add a rule for delete_custom_property: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Docx. Nothing to install.
delete_custom_property is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the delete_custom_property rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for delete_custom_property. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
delete_custom_property is provided by the Docx MCP server (securityronin/docx-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Docx, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
219 Docx tools catalogued and risk-classified — across an index of 43,000+ MCP servers.