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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only the notable return characteristic (total owner count), which is largely redundant given an output schema exists. With annotations carrying the behavioral load, this is adequate but minimal.

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 sentence, front-loaded, with zero filler. Every word (owners, one NFT, total owner count) earns its place.

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?

Output schema exists, so return values need no elaboration, and annotations cover the read-only/open-world profile. For a fully documented 7-param read tool the description is sufficient, though it could have added a routing note toward the collection-level alternative.

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 all seven parameters (chain, contract_address, token_id, limit, cursor, event_types, sort_direction) are already self-documented. The description adds no syntax or format 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 resource ('Owners of one OpenSea NFT') and even the aggregate ('total owner count'), which an agent can distinguish from item-level siblings like opensea_item_offers or collection-level opensea_collection_holders. It does not, however, explicitly name the sibling it differs from, so it stops short of a 5.

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 conditions, and no alternatives are named. The agent is told what the tool returns but not when to prefer it over opensea_item, opensea_collection_holders, or opensea_item_activity.

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