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

No annotations exist, so the description carries the full load. It does add genuine behavioral context — the Blockscout data source and the signed-wallet quota model — but says nothing about pagination, rate limits beyond the trial, error behavior for unindexed chains, or whether a signed wallet is mandatory.

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?

One front-loaded sentence naming the operation and scope, plus a short quota clause. No filler, though the quota emoji/ad copy is slightly noise-like.

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?

Three undocumented parameters, no annotations, and no output schema leave the description as the only guidance — and it omits chain support, the wallet-vs-address distinction, and any sense of what the result set looks like. Inadequate for the schema's ambiguity.

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?

All three parameters (chain, wallet, address) have 0% schema description coverage, and the description never explains them. Critically, it does not disambiguate 'wallet' (presumably the signing/paying identity) from 'address' (the queried holder), which is the single most confusing aspect of this schema.

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 verb ('Lists') and resource ('ERC-721 and ERC-1155 tokens held by a wallet') plus the data provider (Blockscout). It is reasonably distinguishable from siblings like x402-wallet-tokens (fungibles) and x402-nft-owner, though it never explicitly names an alternative.

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 only usage signal is the pricing note ('5 free trial calls per signed wallet'). There is no statement of when to use this versus x402-wallet-tokens, x402-wallet-balance, or x402-nft-owner, and no prerequisites (e.g., chain requirement, address format) are given.

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