AI agents invoke sql_query to trigger actions in SiYuan MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool executes arbitrary SQL queries against the SiYuan database. While the description says 'query', it executes SQL which could include not just SELECT statements but potentially destructive operations like DELETE or DROP. The ability to run arbitrary SQL gives it Execute severity at minimum, with high severity due to potential for data destruction or exfiltration depending on what SQL is permitted.
From the tool's definition 执行 SQL 查询 (Execute SQL query)
Documented attack patterns abuse exactly the kind of access sql_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and SiYuan MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for sql_query:
{
"version": "1",
"default": "deny",
"tools": {
"sql_query": {
"limits": [
{
"counter": "sql_query_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}sql_query stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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执行 SQL 查询. It is categorised as a Execute tool in the SiYuan MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the SiYuan MCP Server MCP server in PolicyLayer and add a rule for sql_query: 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 SiYuan MCP Server. Nothing to install.
sql_query is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the sql_query 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 sql_query. 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.
sql_query is provided by the SiYuan MCP Server MCP server (xgq18237/siyuan_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 52 SiYuan MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
52 SiYuan MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.