AI agents call query_dom to retrieve information from JS Reverse Strong MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
query_dom retrieves DOM elements matching a CSS selector and returns their properties/state. This is a passive observation operation with no side effects, modification, or execution. It fits squarely within the Read category—similar to 'get' or 'fetch' operations.
From the tool's definition Tool is described as 'Query one or multiple elements by CSS selector.' The verb 'query' and the operation of selecting DOM elements are read-only operations that retrieve data without modifying, executing code, or causing side effects.
Documented attack patterns abuse exactly the kind of access query_dom gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and JS Reverse Strong MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for query_dom:
{
"version": "1",
"default": "deny",
"tools": {
"query_dom": {}
}
}query_dom is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Query one or multiple elements by CSS selector. It is categorised as a Read tool in the JS Reverse Strong MCP MCP Server, which means it retrieves data without modifying state.
Register the JS Reverse Strong MCP server in PolicyLayer and add a rule for query_dom: 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 JS Reverse Strong MCP. Nothing to install.
query_dom 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 query_dom 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 query_dom. 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.
query_dom is provided by the JS Reverse Strong MCP server (lwjjike/jsreverser-strong-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from JS Reverse Strong MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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85 JS Reverse Strong MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.