EVM MCP Server

eth_getBalance

Check the balance of any Ethereum or EVM-compatible blockchain account by providing the wallet address and optional block number to query current or historical token holdings.

Instructions

Returns the balance of the account of given address

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": "eth_getBalance"
  }
}

Input Schema

Name	Required	Description	Default
`address`	Yes	Address to check balance for
`blockNumber`	No	Block number or 'latest', 'earliest', 'pending'	latest

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Oct 17, 2025

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states it 'Returns the balance' but doesn't specify units (e.g., wei, ether), error conditions, rate limits, or authentication needs. For a read operation with zero annotation coverage, this is a significant gap in transparency.

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?

The description is a single, efficient sentence with zero waste. It's front-loaded with the core purpose, making it highly concise and well-structured for quick understanding.

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

Completeness2/5

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

Given the complexity of blockchain queries, no annotations, and no output schema, the description is incomplete. It lacks details on return format (e.g., numeric balance in wei), error handling, or dependencies. For a tool with 2 parameters and rich context signals, this minimal description is inadequate.

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?

The schema description coverage is 100%, so the schema already documents both parameters (address and blockNumber) adequately. The description implies the address parameter but doesn't add syntax, format, or contextual details beyond what the schema provides. Baseline 3 is appropriate when the schema handles parameter documentation.

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

Purpose4/5

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

The description clearly states the verb ('Returns') and resource ('balance of the account'), making the purpose specific and understandable. It distinguishes from siblings like eth_getTransactionCount or eth_getCode by focusing on balance retrieval. However, it doesn't explicitly contrast with all siblings, preventing a perfect score.

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

Usage Guidelines2/5

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

No guidance is provided on when to use this tool versus alternatives. The description doesn't mention prerequisites, context, or comparisons to other tools (e.g., eth_call for more complex queries). This leaves the agent without explicit usage instructions.

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