Get the best (lowest priced) listing for a single NFT.
AI agents call get_opensea_best_listing_for_nft to retrieve information from SEI MCP Server V2 without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries OpenSea marketplace data to retrieve pricing information for NFTs. It performs a read-only lookup operation that returns information without creating, modifying, deleting, or executing any state-changing operations. The blast radius of misuse is minimal since the agent merely receives publicly available pricing data.
From the tool's definition Tool name explicitly contains 'get_' and description states 'Get the best (lowest priced) listing' - purely retrieves NFT marketplace data with no side effects or modifications.
Attacks that exploit this kind of access
Get the best (lowest priced) listing for a single NFT. It is categorised as a Read tool in the SEI MCP Server V2 MCP Server, which means it retrieves data without modifying state.
Register the SEI MCP Server V2 MCP server in PolicyLayer and add a rule for get_opensea_best_listing_for_nft: 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 SEI MCP Server V2. Nothing to install.
get_opensea_best_listing_for_nft 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 get_opensea_best_listing_for_nft 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 get_opensea_best_listing_for_nft. 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.
get_opensea_best_listing_for_nft is provided by the SEI MCP Server V2 MCP server (testinguser1111111/sei-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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