AI agents call deleteOneAttachment to permanently remove resources in Twenty MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
This tool permanently deletes an attachment from the Twenty CRM system. Deletion is an irreversible operation that cannot be undone programmatically, making it fall squarely into the Destructive category rather than Write (which is reversible). High severity reflects that an AI agent given this tool could permanently destroy business-critical file attachments without recovery options.
From the tool's definition Tool name contains 'delete' and description states 'Delete One attachment'. The sibling tools on the server are predominantly 'createMany' operations (createManyAttachments, createManyCompanies, etc.), establishing a pattern where this 'deleteOne' operation…
Documented attack patterns abuse exactly the kind of access deleteOneAttachment gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Twenty MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for deleteOneAttachment:
{
"version": "1",
"default": "deny",
"hide": [
"deleteOneAttachment"
]
}deleteOneAttachment 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 One attachment. It is categorised as a Destructive tool in the Twenty MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Twenty MCP Server MCP server in PolicyLayer and add a rule for deleteOneAttachment: 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 Twenty MCP Server. Nothing to install.
deleteOneAttachment 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 deleteOneAttachment 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 deleteOneAttachment. 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.
deleteOneAttachment is provided by the Twenty MCP Server MCP server (jdu278/twenty-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Twenty MCP Server, 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 Twenty MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.