Check if a URL has already been shortened without creating a new short URL
AI agents call contract_url to retrieve information from YOURLS-MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries the YOURLS database to verify whether a URL exists in shortened form, returning information without modifying, deleting, or executing any operations. It is a read-only query that retrieves data about existing shortened URLs.
From the tool's definition Tool description states 'Check if a URL has already been shortened without creating a new short URL' — a pure lookup operation with no side effects.
Attacks that exploit this kind of access
Check if a URL has already been shortened without creating a new short URL. It is categorised as a Read tool in the YOURLS-MCP MCP Server, which means it retrieves data without modifying state.
Register the YOURLS- MCP server in PolicyLayer and add a rule for contract_url: 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 YOURLS-MCP. Nothing to install.
contract_url is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the contract_url 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.
Set action: deny in the PolicyLayer policy for contract_url. 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.
contract_url is provided by the YOURLS- MCP server (kesslerio/yourls-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
contract_url is one line of YOURLS-'s registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
Teams ship this data inside their own products. See what a licence covers →