Retrieves and summarizes all visual changes detected by Percy AI between the latest and previous builds, helping quickly review what has changed in your project.
AI agents call fetchPercyChanges to retrieve information from BrowserStack without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool only queries and retrieves historical visual testing data (Percy build comparisons). It does not modify, execute operations, delete data, or commit financial transactions. The action is purely informational - reviewing existing test results. This is a standard Read operation with minimal risk if misused by an AI agent.
From the tool's definition Tool description states it 'Retrieves and summarizes all visual changes detected by Percy AI between the latest and previous builds' - the verb 'retrieves' and the passive summarization of already-detected changes indicate data retrieval with no side effects.
Attacks that exploit this kind of access
Retrieves and summarizes all visual changes detected by Percy AI between the latest and previous builds, helping quickly review what has changed in your project. It is categorised as a Read tool in the BrowserStack MCP Server, which means it retrieves data without modifying state.
Register the BrowserStack MCP server in PolicyLayer and add a rule for fetchPercyChanges: 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 BrowserStack. Nothing to install.
fetchPercyChanges 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 fetchPercyChanges 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 fetchPercyChanges. 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.
fetchPercyChanges is provided by the BrowserStack MCP server (browserstack/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.