Calculate vitamin D synthesis at a given location and time. Returns sun position, UV index, IU/min, minutes to reach the target dose, MED (sunburn threshold), the peak window, and optional 15-min day / monthly year curves. UV index uses a live satellite-driven forecast where available, with a cle...
Risk signalsHigh parameter count (10 properties)
Part of the D Fetcher server.
Free to start. No card required.
AI agents may call calculate to permanently remove or destroy resources in D Fetcher. Without a policy, an autonomous agent could delete critical data in a loop with no way to undo the damage. PolicyLayer blocks destructive tools by default and requires explicit human approval before enabling them.
Without a policy, an AI agent could call calculate in a loop, permanently destroying resources in D Fetcher. There is no undo for destructive operations. PolicyLayer blocks this tool by default and only allows it when a human explicitly approves the action.
Destructive tools permanently remove data. Block by default. Only enable with explicit approval workflows.
{
"version": "1",
"default": "deny",
"hide": [
"calculate"
]
}See the full D Fetcher policy for all 3 tools.
These attack patterns abuse exactly the kind of access calculate gives an agent. Each links to the full case and the policy that stops it:
Other destructive tools across the catalogue. The same approach applies to each: deny by default, or require human approval.
Calculate vitamin D synthesis at a given location and time. Returns sun position, UV index, IU/min, minutes to reach the target dose, MED (sunburn threshold), the peak window, and optional 15-min day / monthly year curves. UV index uses a live satellite-driven forecast where available, with a clear-sky fallback.. It is categorised as a Destructive tool in the D Fetcher MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the D Fetcher MCP server in PolicyLayer and add a rule for calculate: 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 D Fetcher. Nothing to install.
calculate is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the calculate 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. 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 is provided by the D Fetcher MCP server (https://dfetcher.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 3 D Fetcher tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.