add_task_assignee · Vikunja MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_task_assignee does on Vikunja MCP Server

AI agents use add_task_assignee 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 add_task_assignee needs a policy

This tool modifies task state by adding an assignee relationship. While it creates data (an assignment link), it is reversible and does not permanently delete or execute arbitrary code. The severity is medium because assigning tasks to users could impact workflows if misused by an AI agent (e.g., reassigning all tasks to an attacker), but the operation itself is non-destructive and can be undone.

From the tool's definition The tool name 'add_task_assignee' and description 'Add a user as assignee to a task' indicate a modification operation. This creates or updates a task assignment relationship, which is reversible (the assignment can be removed via a complementary operation).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_task_assignee Rate-limited

add_task_assignee 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": {
    "add_task_assignee": {
      "limits": [
        {
          "counter": "add_task_assignee_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 add_task_assignee

What does the add_task_assignee tool do? +

Add a user as assignee to a task. 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 add_task_assignee? +

Register the Vikunja MCP Server MCP server in PolicyLayer and add a rule for add_task_assignee: 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 add_task_assignee? +

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

Can I rate-limit add_task_assignee? +

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

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

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