Detect whether to pair a light or dark color against a given color for best contrast.
AI agents call use-light-or-dark to retrieve information from Accessible Color Contrast MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves accessibility information based on input colors and returns a recommendation. It has no side effects, does not modify or delete data, does not execute arbitrary commands, and does not involve financial transactions. It is a pure read/query operation that analyzes color contrast properties.
From the tool's definition Tool detects and returns contrast recommendations ('whether to pair a light or dark color') without modifying data, executing code, or triggering external operations. It performs analysis/querying of color properties.
Attacks that exploit this kind of access
Detect whether to pair a light or dark color against a given color for best contrast. It is categorised as a Read tool in the Accessible Color Contrast MCP MCP Server, which means it retrieves data without modifying state.
Register the Accessible Color Contrast MCP server in PolicyLayer and add a rule for use-light-or-dark: 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 Accessible Color Contrast MCP. Nothing to install.
use-light-or-dark 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 use-light-or-dark 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 use-light-or-dark. 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.
use-light-or-dark is provided by the Accessible Color Contrast MCP server (ryelle/a11y-color-contrast-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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