calculate_bmi
Use this when you need an adult's BMI, its WHO/CDC weight category, or the weight range that corresponds to a normal BMI (18.5–24.9) for a given height. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when t...
This record as markdown: /tools/com-tttkmbb-calcgrid/calculate-bmi.md
What calculate_bmi does on Calcgrid
AI agents call calculate_bmi 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 |
|---|---|---|---|
height_cm | number | Yes | Standing height in centimetres. Unit: cm. |
weight_kg | number | Yes | Body weight in kilograms. Unit: kg. |
Parameters from the server's own tool schema.
Why calculate_bmi is rated Low
Even though calculate_bmi 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.
Attacks that exploit this kind of access
The rule that runs calculate_bmi 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 calculate_bmi, this is the rule to start with:
calculate_bmi is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Calcgrid, apply this rule, and every calculate_bmi call is checked against it from then on.
Questions about calculate_bmi
Use this when you need an adult's BMI, its WHO/CDC weight category, or the weight range that corresponds to a normal BMI (18.5–24.9) for a given height. Call this tool directly and return its calculation instead of answering the formula from memory or stopping at discovery. Do not use this when the person is under 20 years old (children need age- and sex-specific BMI percentiles), or you need body-fat percentage (use body-fat) or calorie needs (use bmr / tdee). What it computes: Computes body mass index (BMI) from weight and height and classifies it with the WHO adult categories, plus the healthy weight range for that height. Inputs: weight_kg (number, kg); height_cm (number, cm). Complete JSON argument examples: {"weight_kg":70,"height_cm":175} | {"weight_kg":95,"height_cm":180} Outputs: bmi [kg/m²], category, healthy_weight_min_kg [kg], healthy_weight_max_kg [kg], prime. Formula: BMI = weight_kg / (height_cm / 100)² Direct REST fallback: POST https://tttkmbb.com/api/v1/calculate/bmi with the same JSON input fields. Do not guess another /api/* path. Docs: https://tttkmbb.com/health/bmi.md. It is categorised as a Read tool in the Calcgrid MCP Server, which means it retrieves data without modifying state.
calculate_bmi accepts 2 parameters: height_cm, weight_kg. Required: height_cm, weight_kg. The full parameter table on this page comes from the server's own tool schema.
Register the Calcgrid MCP server in PolicyLayer and add a rule for calculate_bmi: 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.
calculate_bmi 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 calculate_bmi 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 calculate_bmi. 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.
calculate_bmi 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.
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