list_units

List every unit symbol supported by convert_units, grouped by quantity, with names. Use it when a unit symbol is rejected with UNKNOWN_UNIT. Does not convert anything.

SERVERCalcgrid SOURCEhttps://tttkmbb.com/mcp

Low RISK CLASS

Category Read

Parameters 10 required

Recommended Allowedsee the rule below

Registry record Grade D, identity unverified Pull the record →

This record as markdown: /tools/com-tttkmbb-calcgrid/list-units.md

WHAT IT DOES

What list_units does on Calcgrid

AI agents call list_units to retrieve information from Calcgrid without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Parameter	Type	Required	Description
`quantity`	string	—	Optional quantity id to filter (e.g. 'length').

Parameters from the server's own tool schema.

RISK

Why list_units is rated Low

Even though list_units only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

Risk signalsBulk/mass operation — affects multiple targets

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs list_units safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Calcgrid, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For list_units, this is the rule to start with:

list_units Allowed

list_units is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_units": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Calcgrid, apply this rule, and every list_units call is checked against it from then on.

FAQ

Questions about list_units

What does the list_units tool do? +

List every unit symbol supported by convert_units, grouped by quantity, with names. Use it when a unit symbol is rejected with UNKNOWN_UNIT. Does not convert anything. It is categorised as a Read tool in the Calcgrid MCP Server, which means it retrieves data without modifying state.

What parameters does list_units accept? +

list_units accepts 1 parameter: quantity. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on list_units? +

Register the Calcgrid MCP server in PolicyLayer and add a rule for list_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 Calcgrid. Nothing to install.

What risk level is list_units? +

list_units is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit list_units? +

Yes. Add a rate_limit block to the list_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.

How do I block list_units completely? +

Set action: deny in the PolicyLayer policy for list_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.

What MCP server provides list_units? +

list_units is provided by the Calcgrid MCP server (https://tttkmbb.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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