List all supported units for each conversion type or for a specific type.
AI agents call list_supported_units to retrieve information from Unit Converter MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves metadata about supported units without modifying, executing, or affecting any external systems. It is a read-only informational query with no side effects or impact potential.
From the tool's definition Tool name 'list_supported_units' and description 'List all supported units' clearly indicate a query/retrieval operation that returns informational data about available units.
Documented attack patterns abuse exactly the kind of access list_supported_units gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Unit Converter MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for list_supported_units:
{
"version": "1",
"default": "deny",
"tools": {
"list_supported_units": {}
}
}list_supported_units is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List all supported units for each conversion type or for a specific type. It is categorised as a Read tool in the Unit Converter MCP MCP Server, which means it retrieves data without modifying state.
Register the Unit Converter MCP server in PolicyLayer and add a rule for list_supported_units: 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 Unit Converter MCP. Nothing to install.
list_supported_units 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 list_supported_units 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 list_supported_units. 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.
list_supported_units is provided by the Unit Converter MCP server (zazencodes/unit-converter-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Unit Converter MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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16 Unit Converter MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.