AI agents call get_limit_up_down to retrieve information from Cn Financial without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves historical or current market data about stocks that have hit daily price limits (涨停/跌停 - limit up/limit down in Chinese stock markets). It performs no modifications, deletions, financial transactions, or code execution. It is a simple query/fetch operation with no side effects, placing it squarely in the Read category with low severity.
From the tool's definition Tool name 'get_limit_up_down' and description '获取当日涨停板或跌停板股票池' (Get today's limit up/down stock pool) indicates retrieval of market data.
Documented attack patterns abuse exactly the kind of access get_limit_up_down gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Cn Financial, and nothing reaches the server without passing your rules. This is the rule we recommend for get_limit_up_down:
{
"version": "1",
"default": "deny",
"tools": {
"get_limit_up_down": {}
}
}get_limit_up_down is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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获取当日涨停板或跌停板股票池。. It is categorised as a Read tool in the Cn Financial MCP Server, which means it retrieves data without modifying state.
Register the Cn Financial MCP server in PolicyLayer and add a rule for get_limit_up_down: 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 Cn Financial. Nothing to install.
get_limit_up_down 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 get_limit_up_down 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 get_limit_up_down. 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.
get_limit_up_down is provided by the Cn Financial MCP server (ccq1/cn-financial-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Cn Financial, 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.
42 Cn Financial tools catalogued and risk-classified — across an index of 43,000+ MCP servers.