获取MySQL系统变量 Args: pattern: 变量名称匹配模式 (可选, 例如 '%buffer%') global_scope: 是否查询全局变量 (默认为会话变量) Returns: 系统变量的JSON字符串
AI agents call mysql_show_variables to retrieve information from MySQL MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool only retrieves and displays MySQL system configuration variables. It takes optional filter parameters (pattern, scope) but performs no write, delete, execute, or financial operations. The return value is informational only.
From the tool's definition Tool name 'mysql_show_variables' and description 'retrieves MySQL system variables' with read-only arguments (pattern matching and scope selection). Returns JSON data without modification.
Documented attack patterns abuse exactly the kind of access mysql_show_variables gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MySQL MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for mysql_show_variables:
{
"version": "1",
"default": "deny",
"tools": {
"mysql_show_variables": {}
}
}mysql_show_variables 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MySQL系统变量 Args: pattern: 变量名称匹配模式 (可选, 例如 '%buffer%') global_scope: 是否查询全局变量 (默认为会话变量) Returns: 系统变量的JSON字符串. It is categorised as a Read tool in the MySQL MCP Server MCP Server, which means it retrieves data without modifying state.
Register the MySQL MCP Server MCP server in PolicyLayer and add a rule for mysql_show_variables: 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 MySQL MCP Server. Nothing to install.
mysql_show_variables 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 mysql_show_variables 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 mysql_show_variables. 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.
mysql_show_variables is provided by the MySQL MCP Server MCP server (mangooer/mysql-mcp-server-sse). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MySQL 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.
12 MySQL MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.