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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe, external read. The description contributes the return-field inventory and chain scoping, but says nothing about pagination behavior, rate limits, or handling of wallets with no NFTs; with annotations covering safety, a 3 is appropriate.

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?

Two compact sentences, zero waste: the scope and return shape are front-loaded, and the alternative-tool pointer is a short trailing clause.

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, so the description carries the burden of telling the agent what comes back, and it does so with a field list. Pagination and empty-result behavior are left to the schema and unstated, which is a minor gap for a read-only list tool.

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 chain, address, pageSize and pageToken are already documented in the schema. The description only implicitly reinforces the wallet/chain scope and adds no format or syntax detail beyond the schema, so the baseline 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?

States a specific verb and resource (NFTs one wallet holds on one chain) and enumerates the returned fields (collection, name, token id, contract, ERC721/1155 standard, image URL). It also names the sibling it is not (getBalances) so an agent can route without opening either schema.

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?

Gives an explicit when-not condition with the correct alternative: 'For fungible tokens use getBalances.' Beyond that it offers no guidance on related tools such as getTokenHolders or the pagination/chain quirks, so it is clear context but not a full when/when-not map.

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