AI agents call stock_cyq_em to retrieve information from China Stock 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 designed to query and retrieve Chinese stock market information, consistent with the server's purpose of providing 'comprehensive access to Chinese stock market data.' The empty description reduces confidence slightly, but the naming pattern and sibling tools strongly indicate this is a data retrieval tool with no side effects.
From the tool's definition Tool name 'stock_cyq_em' suggests retrieval of stock data (likely 'CYQ' referring to a Chinese stock market metric and 'EM' likely referring to East Money data).
Documented attack patterns abuse exactly the kind of access stock_cyq_em gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and China Stock MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for stock_cyq_em:
{
"version": "1",
"default": "deny",
"tools": {
"stock_cyq_em": {}
}
}stock_cyq_em is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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stock_cyq_em. It is categorised as a Read tool in the China Stock MCP Server MCP Server, which means it retrieves data without modifying state.
Register the China Stock MCP Server MCP server in PolicyLayer and add a rule for stock_cyq_em: 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 China Stock MCP Server. Nothing to install.
stock_cyq_em 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 stock_cyq_em 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 stock_cyq_em. 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.
stock_cyq_em is provided by the China Stock MCP Server MCP server (peikuo/china-stock-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from China Stock MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
351 China Stock MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.