Check if a URL is safe to access. Validates URLs against known dangerous patterns including: - Data exfiltration services (webhook.site, requestbin, etc.) - IP-based URLs (often used to bypass domain filtering) - Suspicious TLDs (.tk, .ml, etc.) - Data URLs (can contain arbitrary content) Args: -...
Risk signalsAccepts URL/endpoint input (url)
Part of the Mund server.
Free to start. No card required.
AI agents call mund_check_url to retrieve information from Mund without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though mund_check_url only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"mund_check_url": {}
}
}See the full Mund policy for all 23 tools.
These attack patterns abuse exactly the kind of access mund_check_url gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Check if a URL is safe to access. Validates URLs against known dangerous patterns including: - Data exfiltration services (webhook.site, requestbin, etc.) - IP-based URLs (often used to bypass domain filtering) - Suspicious TLDs (.tk, .ml, etc.) - Data URLs (can contain arbitrary content) Args: - url (string): The URL to check (required) - tool_name (string): Name of tool attempting access (optional) - agent_id (string): ID of requesting agent (optional) Returns: JSON object with: - url: The checked URL - safe: Boolean indicating if URL is safe - risk_level: 'safe' | 'suspicious' | 'dangerous' - warnings: Array of warning messages if any - blocked: Whether access was blocked. It is categorised as a Read tool in the Mund MCP Server, which means it retrieves data without modifying state.
Register the Mund MCP server in PolicyLayer and add a rule for mund_check_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 Mund. Nothing to install.
mund_check_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 mund_check_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 mund_check_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.
mund_check_url is provided by the Mund MCP server (@weave_protocol/mund). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 23 Mund tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.