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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is established. The description adds value by stating the operation has no cost and by outlining result contents, but it does not go deeper into recency, limits, or data source behavior.

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 concise sentence states exactly what information is returned and adds only the essential cost fact. Nothing is wasted and the key content 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?

For a zero-parameter, read-only tool with complete annotations, the description is sufficient. It tells the caller what result data to expect (balance, usages, expirations, movements) and that the operation is free, so no output schema or further context is strictly necessary.

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 has zero parameters and an empty schema, so parameter semantics are trivially complete. The description does not need to explain parameter meaning and instead focuses on the result content, which is appropriate here.

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 title supplies the verb 'Consultar', and the description names the resource: package balance, per-product usage with expiration, and recent movements. It clearly identifies what information is returned and is distinguishable from siblings like consultar_uso by also covering balance and movements.

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?

The description gives no guidance on when to use this tool versus alternatives such as consultar_uso or consultar_precios. 'No tiene costo' is a pricing note, not a usage condition, so an agent gets little help selecting this tool over nearby siblings.

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