AI agents call web_extract_metadata to retrieve information from Data Apis without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a passive data retrieval tool with no capability to modify, delete, execute code, or transfer funds. The metadata extraction is read-only. While web scraping raises some policy concerns (robots.txt compliance, terms of service), the technical capability is purely informational retrieval. The financial aspect (micropayment) is infrastructure cost, not the tool's functional category.
From the tool's definition Tool extracts metadata (title, author, description, images, links, headings) from URLs—purely retrieving and parsing publicly available information with no modifications, deletions, or external side effects.
Attacks that exploit this kind of access
Extract title, author, description, images, links, and headings from any URL. Costs $0.02 USDC per request via x402 on Base. It is categorised as a Read tool in the Data Apis MCP Server, which means it retrieves data without modifying state.
Register the Data Apis MCP server in PolicyLayer and add a rule for web_extract_metadata: 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 Data Apis. Nothing to install.
web_extract_metadata 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 web_extract_metadata 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 web_extract_metadata. 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.
web_extract_metadata is provided by the Data Apis MCP server (yantrix-ai/x402-apis-mcp-server). 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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