Get input fields for one or more AWS services. Returns field IDs, types, labels, and valid options. Accepts multiple comma-separated service keys. IMPORTANT: When duplicate fields exist with version suffixes (e.g. fieldName and fieldName_v2), ALWAYS use the highest version.
AI agents call get_service_fields to retrieve information from Aws Calculator without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool retrieves metadata about AWS service input fields without modifying, executing, or deleting anything. It is a pure information lookup function similar to a schema query or GET request. No blast radius from misuse beyond information disclosure of field structure.
From the tool's definition Tool description states it 'Get[s] input fields for one or more AWS services' and 'Returns field IDs, types, labels, and valid options.' This is a query/retrieval operation with no side effects.
Documented attack patterns abuse exactly the kind of access get_service_fields gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Aws Calculator, and nothing reaches the server without passing your rules. This is the rule we recommend for get_service_fields:
{
"version": "1",
"default": "deny",
"tools": {
"get_service_fields": {}
}
}get_service_fields is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get input fields for one or more AWS services. Returns field IDs, types, labels, and valid options. Accepts multiple comma-separated service keys. IMPORTANT: When duplicate fields exist with version suffixes (e.g. fieldName and fieldName_v2), ALWAYS use the highest version. It is categorised as a Read tool in the Aws Calculator MCP Server, which means it retrieves data without modifying state.
Register the Aws Calculator MCP server in PolicyLayer and add a rule for get_service_fields: 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 Aws Calculator. Nothing to install.
get_service_fields 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 get_service_fields 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 get_service_fields. 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.
get_service_fields is provided by the Aws Calculator MCP server (musheer360/aws-calculator-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Aws Calculator, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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8 Aws Calculator tools catalogued and risk-classified — across an index of 43,000+ MCP servers.