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

With no annotations, the description carries the full burden. It usefully adds that the tool is free, deterministic, and callable over HTTP/MCP, but it does not explain the response shape, error behavior for malformed addresses, or whether the output is a boolean, normalized address, or checksum details.

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

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

The description is short and front-loads the free/no-payment caveat and the core validation purpose. There is minor repetition with the title, but no wasted sentences.

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

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

There is no output schema and no annotations, so the description should clarify what the tool returns and how invalid addresses are reported. It states what is checked but leaves the agent guessing about the result format, which is important for a validation utility.

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

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

Schema description coverage is 100%, and the single address parameter includes an example. The description does not add syntax or format constraints beyond what the schema already provides, so the baseline score of 3 applies.

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

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

The description names the specific resource (EVM address) and the checks performed: format, lowercase form, and EIP-55 checksum. This distinguishes it from crypto-format siblings such as u_base58 or u_hex, though the phrase 'checksum mode' is slightly ambiguous.

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

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

It gives a clear use case ('before sending funds') and notes MCP/HTTP access, but does not say when to use this versus alternatives like validate or other utility tools. The guidance is implied rather than comparative.

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