AI agents call delete_tiddler to permanently remove resources in Tiddly MCP — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Deletes tiddlers (wiki content) irreversibly without undo capability. This meets the Destructive category definition of 'irreversibly deletes or overwrites data, or actions that cannot be undone (delete, drop, purge, force-push)'. The high severity reflects that an AI agent given this tool could remove important wiki content. Confidence is high because the intent is unambiguous.
From the tool's definition Tool name is 'delete_tiddler' and description states 'Delete a tiddler from the wiki'. Deletion is irreversible.
Documented attack patterns abuse exactly the kind of access delete_tiddler gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Tiddly MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for delete_tiddler:
{
"version": "1",
"default": "deny",
"hide": [
"delete_tiddler"
]
}delete_tiddler 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 tiddler from the wiki. It is categorised as a Destructive tool in the Tiddly MCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Tiddly MCP server in PolicyLayer and add a rule for delete_tiddler: 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 Tiddly MCP. Nothing to install.
delete_tiddler 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_tiddler 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_tiddler. 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_tiddler is provided by the Tiddly MCP server (rryan/tiddly-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Tiddly MCP, 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.
5 Tiddly MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.