AI agents call earnings_premarket_screener to retrieve information from Finviz MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool appears to screen earnings data for premarket conditions—a read-only query operation. No modification, deletion, code execution, or financial transactions are implied. The empty description lowers confidence slightly, but the naming pattern and sibling tools strongly suggest this is a data retrieval/filtering tool used for stock market analysis.
From the tool's definition Tool name 'earnings_premarket_screener' and server context indicating 'stock screening and fundamental analysis capabilities' suggest data retrieval. Description is empty, limiting certainty.
Documented attack patterns abuse exactly the kind of access earnings_premarket_screener gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Finviz MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for earnings_premarket_screener:
{
"version": "1",
"default": "deny",
"tools": {
"earnings_premarket_screener": {}
}
}earnings_premarket_screener is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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earnings_premarket_screener. It is categorised as a Read tool in the Finviz MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Finviz MCP Server MCP server in PolicyLayer and add a rule for earnings_premarket_screener: 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 Finviz MCP Server. Nothing to install.
earnings_premarket_screener 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 earnings_premarket_screener 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 earnings_premarket_screener. 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.
earnings_premarket_screener is provided by the Finviz MCP Server MCP server (tradermonty/finviz-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 35 Finviz MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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35 Finviz MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.