AI agents call account__txlistinternal_byblock to retrieve information from Etherscan MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves internal Ethereum transactions within a block from public blockchain data. It has no side effects, does not modify state, execute code, delete data, or move funds. It is a straightforward query operation that returns existing blockchain information. The low severity reflects minimal blast radius—misuse would only result in querying public data, not unauthorized actions.
From the tool's definition Tool name 'txlistinternal_byblock' and description prefix 'Returns the list of' indicate a query/retrieval operation that fetches blockchain transaction data.
Documented attack patterns abuse exactly the kind of access account__txlistinternal_byblock gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Etherscan MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for account__txlistinternal_byblock:
{
"version": "1",
"default": "deny",
"tools": {
"account__txlistinternal_byblock": {}
}
} account__txlistinternal_byblock is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Returns the list of. It is categorised as a Read tool in the Etherscan MCP MCP Server, which means it retrieves data without modifying state.
Register the Etherscan MCP server in PolicyLayer and add a rule for account__txlistinternal_byblock: 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 Etherscan MCP. Nothing to install.
account__txlistinternal_byblock 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 account__txlistinternal_byblock 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 account__txlistinternal_byblock. 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.
account__txlistinternal_byblock is provided by the Etherscan MCP server (xiaok/etherscan-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Etherscan MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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56 Etherscan MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.