抓取 http/https URL 正文并转为 Markdown；官方 Claude 默认应使用内置 WebFetch，除非用户显式要求 cc-web 或配置允许。
AI agents call fetch_url to retrieve information from CC Web MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and transforms web content into Markdown format. It performs a read-only operation—fetching existing page content and converting its format. There are no side effects, no data modification, no irreversible actions, and no external code execution triggered by the tool itself. The safety note about Claude's built-in WebFetch preference does not change the operational category.
From the tool's definition Tool description states it '抓取 http/https URL 正文并转为 Markdown' (fetches HTTP/HTTPS URL content and converts to Markdown). The verb '抓取' (fetch/retrieve) and the conversion operation indicate data retrieval with no modification, deletion, or code execution.
Documented attack patterns abuse exactly the kind of access fetch_url gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and CC Web MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for fetch_url:
{
"version": "1",
"default": "deny",
"tools": {
"fetch_url": {}
}
}fetch_url is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
抓取 http/https URL 正文并转为 Markdown；官方 Claude 默认应使用内置 WebFetch，除非用户显式要求 cc-web 或配置允许。. It is categorised as a Read tool in the CC Web MCP MCP Server, which means it retrieves data without modifying state.
Register the CC Web MCP server in PolicyLayer and add a rule for fetch_url: 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 CC Web MCP. Nothing to install.
fetch_url 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 fetch_url 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 fetch_url. 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.
fetch_url is provided by the CC Web MCP server (jcdizzy/cc-web-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from CC Web MCP, 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.
4 CC Web MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.