MCP Etherscan Server

get-ens-name

Resolve an Ethereum address to its primary ENS name on mainnet.

Instructions

Get the ENS name for an Ethereum address (mainnet only)

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "address": "<address>"
    },
    "name": "get-ens-name"
  }
}

Input Schema

Name	Required	Description	Default
`address`	Yes	Ethereum address (0x format)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.1.2Mar 6, 2026

TDQS

A3.5/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided, so description carries full burden. It only says 'get ENS name' without disclosing that address must have a reverse record, rate limits, or error handling. Minimal behavioral info.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence with no fluff. Perfectly front-loaded and concise for a simple tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Adequate for a one-param, no-output-schema tool, but lacks explanation of return value format or behavior when no ENS name exists. Sufficient but not thorough.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with a clear pattern and description for 'address'. The description adds no extra meaning beyond the schema, meeting baseline for high coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the action (get ENS name) and resource (Ethereum address), with the constraint 'mainnet only', which distinguishes it from other blockchain-related sibling tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Implied usage: use when needing to resolve an ENS name from an address. No explicit guidance on when not to use or alternatives among 23 siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.