AI agents call read_diagram_content to retrieve information from Document Reader 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 and extracts information from diagram/chart content through structural image analysis. It performs no write, delete, execute, or financial operations—it only reads and interprets data from visual elements. The action is reversible with no side effects, matching the 'Read' category definition.
From the tool's definition Tool name 'read_diagram_content' and description indicates it 'directly reads diagram content' and performs 'analysis understanding of diagrams' without modifying, deleting, or executing external operations.
Documented attack patterns abuse exactly the kind of access read_diagram_content gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Document Reader MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for read_diagram_content:
{
"version": "1",
"default": "deny",
"tools": {
"read_diagram_content": {}
}
}read_diagram_content is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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直接读取图表内容，无需复杂OCR配置，基于图像结构分析理解图表. It is categorised as a Read tool in the Document Reader MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Document Reader MCP Server MCP server in PolicyLayer and add a rule for read_diagram_content: 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 Document Reader MCP Server. Nothing to install.
read_diagram_content 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 read_diagram_content 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 read_diagram_content. 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.
read_diagram_content is provided by the Document Reader MCP Server MCP server (qitianfeng/document-reader-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Document Reader MCP Server, 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.
6 Document Reader MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.