create_tiddler · TiddlyWiki MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_tiddler does on TiddlyWiki MCP Server

AI agents use create_tiddler to create or update resources in TiddlyWiki MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your TiddlyWiki MCP Server environment.

WHY IT NEEDS A POLICY

Why create_tiddler needs a policy

Creating new tiddlers (wiki pages/notes) is a Write operation—it modifies wiki state by adding content. The severity is medium rather than low because an AI agent could create many tiddlers, spam content, or inject malicious metadata via arbitrary custom fields; however, it's not Destructive (reversible), Execute (no code execution), or Financial.

From the tool's definition Tool name 'create_tiddler' and description state it 'Create a new tiddler' with support for 'arbitrary custom fields'. This is a create operation that adds new data to the wiki reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_tiddler Rate-limited

create_tiddler stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_tiddler": {
      "limits": [
        {
          "counter": "create_tiddler_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches TiddlyWiki MCP Server, so you can run agents against it safely.

FAQ

Questions about create_tiddler

What does the create_tiddler tool do? +

Create a new tiddler. Shows a preview and requests approval before creating. Supports arbitrary custom fields beyond the standard ones (e.g., caption, summary, author, or any TiddlyWiki field). It is categorised as a Write tool in the TiddlyWiki MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_tiddler? +

Register the TiddlyWiki MCP Server MCP server in PolicyLayer and add a rule for create_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 TiddlyWiki MCP Server. Nothing to install.

What risk level is create_tiddler? +

create_tiddler is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_tiddler? +

Yes. Add a rate_limit block to the create_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.

How do I block create_tiddler completely? +

Set action: deny in the PolicyLayer policy for create_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.

What MCP server provides create_tiddler? +

create_tiddler is provided by the TiddlyWiki MCP Server MCP server (ppetru/tiddlywiki-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.