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

readOnlyHint and openWorldHint already establish this as a safe external read, so the description carries a lower burden. It adds the contents of the returned record, which is mildly useful context, but says nothing about rate limits, freshness, or error cases for a missing token.

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?

A single front-loaded sentence with zero filler. Every element listed earns its place by previewing the returned fields.

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?

An output schema exists, so return-value detail is not strictly required, and annotations cover the safety profile. The definition is adequate for a simple detail lookup, with only usage framing missing.

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 coverage is 100% with all three required parameters documented (chain, contract_address, token_id), so the schema does the work. The description adds no syntax or format detail beyond it, which matches the baseline 3 for high-coverage schemas.

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?

Names the resource (a single OpenSea NFT) and enumerates the payload (traits, rarity rank, owner, best listing, best offer), which implicitly distinguishes it from narrower siblings like opensea_item_listings or opensea_item_offers. It lacks an explicit retrieval verb, but the identity and scope are unambiguous.

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 when-to-use guidance, no prerequisites, and no named alternatives. The agent gets no help deciding between this and the many opensea_item_* siblings.

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