firefly_create_tag · Firefly III MCP Server MCP

WHAT IT DOES

What firefly_create_tag does on Firefly III MCP Server

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

WHY IT NEEDS A POLICY

Why firefly_create_tag needs a policy

This tool creates a new tag, which is a reversible write operation. Tags are metadata used to organize and label transactions. Creating a tag has minimal direct financial impact—it does not move money, execute code, or irreversibly delete data. The operation is fully reversible through deletion.

From the tool's definition Tool name contains 'create' and description states 'Create a new tag for labeling transactions.' This adds a new tag entity to the Firefly III system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

firefly_create_tag Rate-limited

firefly_create_tag 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": {
    "firefly_create_tag": {
      "limits": [
        {
          "counter": "firefly_create_tag_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 Firefly III MCP Server, so you can run agents against it safely.

FAQ

Questions about firefly_create_tag

What does the firefly_create_tag tool do? +

Create a new tag for labeling transactions. It is categorised as a Write tool in the Firefly III 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 firefly_create_tag? +

Register the Firefly III MCP Server MCP server in PolicyLayer and add a rule for firefly_create_tag: 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 Firefly III MCP Server. Nothing to install.

What risk level is firefly_create_tag? +

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

Can I rate-limit firefly_create_tag? +

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

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

firefly_create_tag is provided by the Firefly III MCP Server MCP server (przbadu/firefly-iii-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.