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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description carries little additional behavioral burden. However, it adds only the HTTP endpoint (GET) and nothing about pagination, filtering semantics, or response characteristics—limited value beyond the annotations.

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?

The description is extremely concise and front-loaded, but it is under-specified. It avoids fluff yet fails to include essential parameter or behavior information, making it minimally sized but not appropriately sized for a tool with three undocumented parameters.

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 simple read-only list operation, the description plus annotations cover the safety profile, but the tool is not fully understandable: parameter semantics are absent, no output format is described, and no filter or account context is given. The agent would struggle to invoke this tool correctly in a non-trivial way.

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 0% with three parameters (account, filters, alterado_apos) and no descriptions. The tool description does not compensate by explaining any parameter meaning, leaving the agent with no information about what these fields do or expect.

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 states a specific verb ('Lista') and resource ('transportadoras'), clearly indicating the tool lists carriers. The HTTP endpoint further clarifies the scope and distinguishes it from other mercos_list_* siblings.

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 guidance is given on when to use this tool versus alternatives, nor any exclusions or prerequisites. The description only states what it does, leaving the agent to infer usage solely from the resource type.

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