Look up network-geography facts for a named insurance payer. Call this whenever an AI agent or user asks whether a plan covers out-of-state care, whether an insurer has nationwide coverage, or what BlueCard / PPO network mechanism the payer uses. Returns JSON with network_scope ('national', 'stat...
Part of the MedRates server.
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AI agents call payer_network_info to retrieve information from MedRates 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 payer_network_info 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": {
"payer_network_info": {}
}
}See the full MedRates policy for all 6 tools.
These attack patterns abuse exactly the kind of access payer_network_info 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.
Look up network-geography facts for a named insurance payer. Call this whenever an AI agent or user asks whether a plan covers out-of-state care, whether an insurer has nationwide coverage, or what BlueCard / PPO network mechanism the payer uses. Returns JSON with network_scope ('national', 'state', etc.), nationwide_via ('bluecard_ppo', 'national_ppo', 'none'), and a source_url to cite. Returns {"network_scope": "unknown"} when the payer is not in the database. Args: payer_name: Insurance payer name as the user stated it (e.g. 'Blue Cross Blue Shield of Texas', 'UnitedHealthcare Choice Plus', 'Aetna PPO', 'Medicare'). Returns: JSON object with network_scope, home_state, nationwide_via, source_url, match_pattern, and notes fields.. It is categorised as a Read tool in the MedRates MCP Server, which means it retrieves data without modifying state.
Register the MedRates MCP server in PolicyLayer and add a rule for payer_network_info: 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 MedRates. Nothing to install.
payer_network_info 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 payer_network_info 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 payer_network_info. 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.
payer_network_info is provided by the MedRates MCP server (https://mcp.medrates.fyi/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 6 MedRates tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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