Given a product (by Lowvyn ID or retailer URL), return the same physical product on other Canadian retailers with their current prices and savings. Uses verified UPC matches. Use this when a user wants to know 'can I get this cheaper somewhere else?'.
Part of the Lowvyn server.
Free to start. No card required.
AI agents call find_cheaper to retrieve information from Lowvyn 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 find_cheaper 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": {
"find_cheaper": {}
}
}See the full Lowvyn policy for all 7 tools.
These attack patterns abuse exactly the kind of access find_cheaper 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.
Given a product (by Lowvyn ID or retailer URL), return the same physical product on other Canadian retailers with their current prices and savings. Uses verified UPC matches. Use this when a user wants to know 'can I get this cheaper somewhere else?'.. It is categorised as a Read tool in the Lowvyn MCP Server, which means it retrieves data without modifying state.
Register the Lowvyn MCP server in PolicyLayer and add a rule for find_cheaper: 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 Lowvyn. Nothing to install.
find_cheaper 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 find_cheaper 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 find_cheaper. 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.
find_cheaper is provided by the Lowvyn MCP server (https://api.lowvyn.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Lowvyn 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.