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

No annotations are provided, so the description carries the full disclosure burden. It adds only the free-trial quota note ("5 free trial calls per registered wallet"). It does not disclose return format, error behavior for unknown accounts, whether parameters are mutually exclusive, or any auth/precondition requirements. "Lookup" implies read-only, but the safety profile is otherwise unstated.

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-loaded: the purpose statement appears first, followed by the trial note. The only waste is the "Account Age:" prefix, which merely restates the tool name. Overall it is appropriately compact for the information it conveys.

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?

With three optional parameters, no required parameters, no output schema, and no annotations, the description leaves critical ambiguity: an agent cannot tell whether chain/wallet/address are alternatives or complements, what a valid call looks like, or what the response contains. For a blockchain lookup tool this is a significant completeness gap.

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%, so the baseline is 3 even with no parameter info in the description. However, the schema descriptions are tautological ("Chain to process," "Wallet to process," "Address to process") and add no real meaning. The description does not compensate by clarifying the relationship between wallet and address, chain format expectations, or which parameters are needed for a valid lookup.

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 states a specific verb and resource: "Blockchain account age lookup." This clearly differentiates the tool from siblings like x402-domain-age (domain age) and x402-wallet-balance (balance). It loses one point because it is brief and does not explicitly contrast itself with the closest wallet/blockchain siblings, leaving some differentiation to inference.

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?

No guidance is given on when to use this tool versus alternatives among the large sibling set (e.g., x402-wallet-intel, x402-wallet-activity, x402-block-explorer). There is no when/when-not guidance, no prerequisites, and no clarification of whether wallet and address are alternative inputs or both required. The only usage-adjacent info is the free-trial limit, which is a quota note, not selection guidance.

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