feed_item_attachment_upload · Starling Bank MCP

WHAT IT DOES

What feed_item_attachment_upload does on Starling Bank

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

WHY IT NEEDS A POLICY

Why feed_item_attachment_upload needs a policy

This tool creates or modifies a transaction's attachments, which is reversible (attachments can be removed). It affects financial records but does not move money, delete data, or execute arbitrary code.

From the tool's definition Tool name 'feed_item_attachment_upload' and description 'Upload an attachment to a feed item' indicate a create/modify operation that adds data to an existing transaction record.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

feed_item_attachment_upload Rate-limited

feed_item_attachment_upload 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": {
    "feed_item_attachment_upload": {
      "limits": [
        {
          "counter": "feed_item_attachment_upload_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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

FAQ

Questions about feed_item_attachment_upload

What does the feed_item_attachment_upload tool do? +

Upload an attachment to a feed item (transaction). Provide either base64 encoded attachment data or a file path (recommended). It is categorised as a Write tool in the Starling Bank MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on feed_item_attachment_upload? +

Register the Starling Bank MCP server in PolicyLayer and add a rule for feed_item_attachment_upload: 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 Starling Bank. Nothing to install.

What risk level is feed_item_attachment_upload? +

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

Can I rate-limit feed_item_attachment_upload? +

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

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

feed_item_attachment_upload is provided by the Starling Bank MCP server (starling-bank-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.