bulk_shorten_urls · Url Shortener MCP: Risk & Policy

WHAT IT DOES

What bulk_shorten_urls does on Url Shortener

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

WHY IT NEEDS A POLICY

Why bulk_shorten_urls needs a policy

This tool creates new shortened URL records in bulk. It is a Write operation (reversible via delete_url/delete_all_urls siblings). The blast radius is medium because an agent could create up to 20 short links per call, potentially spamming or creating misleading redirects, but it does not delete data or move money.

From the tool's definition 'Shorten multiple URLs in a single call' — creates short links (new records) for up to 20 URLs, returning per-URL results including slugs

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

bulk_shorten_urls Rate-limited

bulk_shorten_urls 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": {
    "bulk_shorten_urls": {
      "limits": [
        {
          "counter": "bulk_shorten_urls_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 Url Shortener, so you can run agents against it safely.

FAQ

Questions about bulk_shorten_urls

What does the bulk_shorten_urls tool do? +

Shorten multiple URLs in a single call (max 20). Returns per-URL results including any errors. Each successful result includes estimatedTokensSaved — the per-substitution token saving if that slug is used in place of the full URL in future context. Savings are only realized when slugs are reused; this field does not account for the upfront cost of this tool call. It is categorised as a Write tool in the Url Shortener MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on bulk_shorten_urls? +

Register the Url Shortener MCP server in PolicyLayer and add a rule for bulk_shorten_urls: 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 Url Shortener. Nothing to install.

What risk level is bulk_shorten_urls? +

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

Can I rate-limit bulk_shorten_urls? +

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

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

bulk_shorten_urls is provided by the Url Shortener MCP server (michaelshumshum/url-shortener-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.