AI agents call feishu_doc_fetch to retrieve information from Lark Cli without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves/queries document content from Feishu by accepting a document URL or token as input. It has no side effects—no data is created, modified, deleted, or executed. The action is purely read-only, matching the 'Read' category definition. Severity is low because unauthorized document access poses containment risk but no destructive or financial damage.
From the tool's definition Tool name 'feishu_doc_fetch' and description '读取一篇飞书文档的内容' (reads the content of a Feishu document) indicate data retrieval with no modification or deletion capability.
Attacks that exploit this kind of access
读取一篇飞书文档的内容（传文档 URL 或 token）. It is categorised as a Read tool in the Lark Cli MCP Server, which means it retrieves data without modifying state.
Register the Lark Cli MCP server in PolicyLayer and add a rule for feishu_doc_fetch: 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 Lark Cli. Nothing to install.
feishu_doc_fetch 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 feishu_doc_fetch 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 feishu_doc_fetch. 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.
feishu_doc_fetch is provided by the Lark Cli MCP server (yoreland/lark-cli-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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