AI agents call getObjectUrl to retrieve information from Tencent Cloud COS MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves metadata (a signed URL) to access stored objects. It does not create, modify, delete, or execute code. It is purely a read operation that enables authorized downloading of files. The signing mechanism ensures proper access control. The low severity reflects that it only exposes existing data through a properly authenticated URL generation mechanism, with no side effects or ability to modify data.
From the tool's definition getObjectUrl generates a signed download link for files in a storage bucket. The description states '获取存储桶内的文件的带签名的下载链接' (get signed download link for files in storage bucket).
Documented attack patterns abuse exactly the kind of access getObjectUrl gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Tencent Cloud COS MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for getObjectUrl:
{
"version": "1",
"default": "deny",
"tools": {
"getObjectUrl": {}
}
}getObjectUrl is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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获取存储桶内的文件的带签名的下载链接. It is categorised as a Read tool in the Tencent Cloud COS MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Tencent Cloud COS MCP Server MCP server in PolicyLayer and add a rule for getObjectUrl: 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 Tencent Cloud COS MCP Server. Nothing to install.
getObjectUrl 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 getObjectUrl 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 getObjectUrl. 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.
getObjectUrl is provided by the Tencent Cloud COS MCP Server MCP server (tencent/cos-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 21 Tencent Cloud COS MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
21 Tencent Cloud COS MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.