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

With no annotations, the description carries the full behavioral burden. It discloses a trial/payment constraint ('5 free trial calls per signed wallet') but omits permissions, what signing is required, rate limits beyond the trial, error behavior, and what the returned 'age' represents.

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 purpose is front-loaded in the first clause and the description is brief. The trial-call sentence and emoji add minor noise, but overall it is compact and easy to scan.

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?

For a tool with three undocumented parameters, no annotations, and no output schema, the description is incomplete. It does not clarify wallet vs address, chain input format, whether outputs are days or timestamps, or the authentication/signing requirement implied by 'signed wallet'.

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 0% for three parameters, so the description must compensate but does not. It implies a chain enum through the four chain names and hints at wallet signing, but leaves the roles of wallet versus address completely undefined.

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?

States a specific resource and operation — blockchain account age lookup — and names four supported chains, which distinguishes it from generic siblings like x402-age and x402-domain-age. It is clear enough to select against most siblings, but does not explicitly name an alternative tool.

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?

The description gives no guidance on when to use this tool versus siblings such as x402-wallet-activity, x402-onchain, or x402-age. The only usage-adjacent sentence covers free trial calls, which is pricing information rather than invocation guidance.

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