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

Annotations already declare readOnly/idempotent/closed-world, so the description is free to add scope: results are limited to currently available listings in the iHelpU marketplace in RS. It also discloses the result shape (price, condition, battery, warranty, store, purchase link), which matters because there is no output schema.

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 sentences: the first covers what is searched and where, the second covers filters and return fields. No filler, and the identifying scope (marketplace, RS, available now) is front-loaded.

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?

All parameters are optional and fully documented in the schema, and the missing output schema is compensated by the one-line description of returned fields. Minor gaps remain: no mention of behavior when nothing matches, and the default result count is only in the schema.

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 the six parameters are fully documented in the schema itself. The description restates five of the six filters (omitting limite) without adding syntax or semantics beyond what the schema gives, so the baseline of 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+resource: searches used/semi-new iPhones (and other Apple) currently available on the iHelpU marketplace in RS. The list-and-filter nature plus the enumerated return fields separates it in spirit from detalhes_aparelho and preco_iphone_usado, but no sibling is named explicitly.

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?

Usage is implied by 'disponíveis agora' and the filter list, so an agent can infer this is the browse/discovery entry point. However, there is no explicit 'use this when... instead of detalhes_aparelho / preco_iphone_usado' routing, and no statement of when the tool is the wrong choice.

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