update_filter · Vikunja MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_filter does on Vikunja MCP Server

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

WHY IT NEEDS A POLICY

Why update_filter needs a policy

This tool creates or modifies data reversibly by updating filter definitions. While filters are configuration data rather than primary task/project data, unauthorized modifications could disrupt task organization, visibility, and workflow. However, since filters can be re-edited or restored, this is Write rather than Destructive.

From the tool's definition update_filter modifies an existing saved filter configuration within Vikunja, which is a reversible change to data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_filter Rate-limited

update_filter 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": {
    "update_filter": {
      "limits": [
        {
          "counter": "update_filter_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 Vikunja MCP Server, so you can run agents against it safely.

FAQ

Questions about update_filter

What does the update_filter tool do? +

Update a saved filter. It is categorised as a Write tool in the Vikunja 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 update_filter? +

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

What risk level is update_filter? +

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

Can I rate-limit update_filter? +

Yes. Add a rate_limit block to the update_filter 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 update_filter completely? +

Set action: deny in the PolicyLayer policy for update_filter. 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 update_filter? +

update_filter is provided by the Vikunja MCP Server MCP server (lindenlion/vikunja-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.