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

With no annotations, the description carries the full transparency burden and does so well: it discloses direct mainnet access, freshness (not cache), returned fields, per-request limit, and the block-specific nature of the ownerOf proof. This goes well beyond the minimal requirements.

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?

Each sentence serves a distinct purpose: main function, return fields, usage constraint, and an important limitation about marketplace listings. The description is well-organized, paced, and front-loaded with the core action.

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?

Given no output schema, the description explicitly names all four return fields (owner_atual, rpc_usado, bloco consultado, verificado_em), which is essential for a complete tool description. It also covers the only parameter, behavioral constraints, and comparisons to sibling tools, making it fully self-contained.

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% and the description adds meaningful context: it emphasizes on-chain freshness ('agora mesmo on-chain') and directs users to nft_catalogo for valid token_id values, which is not present in the schema. This compensates for the schema's bare parameter description.

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 clearly states the tool reads the actual owner of one specific token directly from Ethereum mainnet via ownerOf, differentiating it from nft_catalogo which lists all tokens. The verb 'Le' (reads) and resource 'dono real de UM token' are specific and 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?

Explicitly says this is for real-time on-chain owner confirmation, not a cache, and that it only accepts one token_id per request, pointing to nft_catalogo as the alternative for listing all 65 tokens. It also clarifies that ownerOf does not prove marketplace listing, setting proper expectations.

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