assign_tags · Things Cloud MCP: Risk & Policy

WHAT IT DOES

What assign_tags does on Things Cloud MCP

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

WHY IT NEEDS A POLICY

Why assign_tags needs a policy

Assigning or replacing tags on a task is a non-destructive modification operation. It changes task state but does not delete or irreversibly alter data. Severity is medium because an agent could misuse this to strip important organizational tags from many tasks, disrupting workflow, though the action remains reversible.

From the tool's definition Tool description states 'Replace the tags on a task' — this modifies task metadata. Sibling tools include destructive operations (delete_task, delete_project) and other writes (create_task, create_project), confirming a write-capable server.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

assign_tags Rate-limited

assign_tags 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": {
    "assign_tags": {
      "limits": [
        {
          "counter": "assign_tags_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 Things Cloud MCP, so you can run agents against it safely.

FAQ

Questions about assign_tags

What does the assign_tags tool do? +

Replace the tags on a task. It is categorised as a Write tool in the Things Cloud MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on assign_tags? +

Register the Things Cloud MCP server in PolicyLayer and add a rule for assign_tags: 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 Things Cloud MCP. Nothing to install.

What risk level is assign_tags? +

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

Can I rate-limit assign_tags? +

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

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

assign_tags is provided by the Things Cloud MCP server (nkootstra/things). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.