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

With no annotations, the description carries the full behavioral burden. It does disclose the returned content (prices and descriptions), which implies a read-only enumeration of all offerings, but it says nothing about pagination, ordering, auth needs, or whether "todos" means unfiltered and complete.

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 short sentence with no filler; the key fact (full list with pricing and descriptions) is front-loaded and nothing is wasted.

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?

For a trivial zero-parameter listing tool with no output schema, the description covers what the tool returns (prices, descriptions). Minor gaps remain around ordering and pagination, but nothing essential to invoking it is 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?

The tool takes zero parameters, so per the rules the baseline is 4. No parameter semantics are needed and the description does not misrepresent any inputs.

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 ("Lista") and resource ("planos e assinaturas oferecidos"), so an agent knows it enumerates available plans. It does not explicitly differentiate itself from the other list-style siblings (listar_categorias, buscar_produtos), though the resource noun makes the distinction reasonably self-evident.

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?

There is no guidance on when to use this versus buscar_produtos or listar_categorias, no stated prerequisites, and no exclusions. Usage must be inferred entirely from the resource name.

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