Underground Cultural District MCP Server

convert-eth-units

Convert numeric values between Wei, Gwei, and ETH units by specifying the source and target denominations.

Instructions

Convert between Wei, Gwei, and ETH.

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": {
      "value": "<value>",
      "from": "<from>",
      "to": "<to>"
    },
    "name": "convert-eth-units"
  }
}

Input Schema

Name	Required	Description
`value`	Yes	Numeric value
`from`	Yes
`to`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv4.1.0Apr 17, 2026

TDQS

B3.2/5.0

Behavior2/5

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

With no annotations, the description must fully disclose behavior. It only states the conversion action without detailing edge cases, input format constraints (e.g., decimal precision, negative values), or output format. This is a significant gap for a tool that could behave unexpectedly with non-numeric or extreme inputs.

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

Conciseness4/5

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

The description is a single, front-loaded sentence with no wasted words. However, it sacrifices crucial details for brevity, so it's not a perfect 5.

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 parameter count of 3, no output schema, and no annotations, the description is insufficient. It does not explain the Ethereum unit hierarchy, input validation rules, or return value format. An agent unfamiliar with ETH units would lack necessary context to use the tool correctly.

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

Parameters2/5

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

The schema has low coverage (33%) with only 'value' having a generic description ('Numeric value'). The description adds no meaning beyond the schema; it does not explain the enum values (wei, gwei, eth) or clarify the 'value' format (e.g., string integer? decimal?). It fails to compensate for the schema's low 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?

The description clearly states the verb 'Convert' and the resources 'Wei, Gwei, and ETH', making the tool's purpose specific and unambiguous. It distinguishes itself from sibling tools like convert-timestamp, which handles timestamps, by explicitly naming Ethereum units.

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?

The description implies when to use the tool (when needing conversion between ETH units) but provides no explicit guidance on when not to use it or alternatives. There are no other tools for ETH unit conversion, so the lack of exclusion is acceptable, but the description could be more prescriptive.

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