Get a list of counties within a state with their 3-digit FIPS codes.
AI agents call aqs_list_counties to retrieve information from EPA Air Quality System (AQS) MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a straightforward data query operation that retrieves county information indexed by state. It has no side effects—it neither modifies data, executes code, deletes records, nor involves financial transactions. The 'list' and 'get' verbs confirm read-only semantics. Severity is low because misuse would only expose publicly available geographic reference data with minimal impact.
From the tool's definition Tool name 'aqs_list_counties' and description 'Get a list of counties within a state with their 3-digit FIPS codes' indicate a retrieval operation that returns structured data about geographic entities without any modification, deletion, or execution of…
Attacks that exploit this kind of access
Get a list of counties within a state with their 3-digit FIPS codes. It is categorised as a Read tool in the EPA Air Quality System (AQS) MCP Server MCP Server, which means it retrieves data without modifying state.
Register the EPA Air Quality System (AQS) MCP Server MCP server in PolicyLayer and add a rule for aqs_list_counties: 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 EPA Air Quality System (AQS) MCP Server. Nothing to install.
aqs_list_counties 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 aqs_list_counties 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 aqs_list_counties. 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.
aqs_list_counties is provided by the EPA Air Quality System (AQS) MCP Server MCP server (tyson-swetnam/aqs-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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