delete_attachment

THE RISK

Critical Risk

Why delete_attachment needs a policy

Destructive category applies because the tool permanently removes data without recovery mechanism. While the blast radius is limited to individual attachments rather than entire datasets, deletion is irreversible. Severity is high rather than critical because impact is scoped to single attachments; critical would apply if this could cascade-delete or wipe entire knowledge bases.

From the tool's definition delete_attachment performs irreversible deletion of file attachments. The verb 'delete' indicates data removal that cannot be undone.

Documented attack patterns abuse exactly the kind of access delete_attachment gives an agent:

POLICY

How to control delete_attachment

PolicyLayer is an MCP gateway — it sits between your AI agents and TheBrain MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for delete_attachment:

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "delete_attachment"
  ]
}

delete_attachment disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register TheBrain MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More TheBrain MCP Server tools

Destructive delete_link Delete a link Destructive delete_thought Delete a thought Write append_to_note Append content to an existing note Write add_file_attachment Add a file attachment (including images) to a thought Write add_url_attachment Add a URL attachment to a thought Write create_link Create a link between two thoughts with visual properties Write create_or_update_note Create or update a note with markdown content Write create_thought Create a new thought with optional visual properties

All 26 TheBrain MCP Server tools →

Destructive tools on other servers

Android Forensics ADB MCP Server create_full_backup 0xarchive web3_revoke_key Frida Game Hacking MCP clear_scan cPanel MCP Server clear_spam_box

Go deeper

Critical-risk tools in TheBrain MCP Server → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about delete_attachment

What does the delete_attachment tool do? +

Delete an attachment. It is categorised as a Destructive tool in the TheBrain MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on delete_attachment? +

Register the TheBrain MCP Server MCP server in PolicyLayer and add a rule for delete_attachment: 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 TheBrain MCP Server. Nothing to install.

What risk level is delete_attachment? +

delete_attachment is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit delete_attachment? +

Yes. Add a rate_limit block to the delete_attachment 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.

How do I block delete_attachment completely? +

Set action: deny in the PolicyLayer policy for delete_attachment. 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.

What MCP server provides delete_attachment? +

delete_attachment is provided by the TheBrain MCP Server MCP server (redmorestudio/thebrain-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every TheBrain MCP Server tool call.

Start from TheBrain MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →