get_luminance

Calculate relative luminance of a color.

SERVERTinyFn SOURCEhttps://api.tinyfn.io/mcp/all/

Low RISK CLASS

Category Read

Parameters 11 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-tinyfn-tinyfn/get-luminance.md

WHAT IT DOES

What get_luminance does on TinyFn

AI agents call get_luminance to retrieve information from TinyFn 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
`hex_color`	string	Yes	Hex color

Parameters from the server's own tool schema.

RISK

Why get_luminance is rated Low

This is a deterministic mathematical function that computes and returns a color property value. It retrieves/calculates information without modifying state, creating resources, executing external code, deleting data, or moving money. It poses minimal security risk.

From the tool's definition Tool name 'get_luminance' and description 'Calculate relative luminance of a color' indicate a pure calculation/retrieval operation with no side effects.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs get_luminance safely

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

get_luminance Allowed

get_luminance 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": {
    "get_luminance": {}
  }
}

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

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

FAQ

Questions about get_luminance

What does the get_luminance tool do? +

Calculate relative luminance of a color. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.

What parameters does get_luminance accept? +

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

How do I enforce a policy on get_luminance? +

Register the TinyFn MCP server in PolicyLayer and add a rule for get_luminance: 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 TinyFn. Nothing to install.

What risk level is get_luminance? +

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

Can I rate-limit get_luminance? +

Yes. Add a rate_limit block to the get_luminance 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 get_luminance completely? +

Set action: deny in the PolicyLayer policy for get_luminance. 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 get_luminance? +

get_luminance is provided by the TinyFn MCP server (https://api.tinyfn.io/mcp/all/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on TinyFn, and thousands of servers like it.

This server

All 572 TinyFn tools →

Across the catalogue

get_cocktail_by_category on Cocktails RAG MCP Server →get_torrent_detail on M-Team MCP Server →aiva_get_affiliate on AIVA MCP Server →get-chuck-categories on Jokes MCP Server → The MCP Attack Database →

Guides

Roll out MCP under one policy →Data exfiltration →MCP token cost →