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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint, so the safety profile is covered. The description adds one genuinely useful behavioral fact — that the list is private and scoped to an account session or a guest "edm_" identity — but the reference is truncated with an ellipsis, leaving the guest mechanism underspecified.

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?

It is a single short sentence with the resource front-loaded, which is structurally sound. But "e seleção" sits in the purpose clause without adding meaning, and the truncated "edm_…." reference weakens the sentence rather than shortening it cleanly.

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?

There is no output schema and no parameters, so the description is the only place an agent could learn what this returns — yet it says nothing about the returned company fields, ordering, counts, or which company is flagged as selected. For a zero-parameter read tool with no output schema, that is a substantive gap.

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 baseline the description is not expected to document any. Its mention of session/guest context is the closest thing to an input qualifier, though it is not a declared parameter.

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 names the resource ("lista privada de empresas") and identifies it as the user's own list, which distinguishes it loosely from buscar_empresa. However, the trailing "e seleção" is ambiguous — it is unclear whether this tool performs a selection or merely reflects the currently selected company, and no sibling is named for contrast.

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?

"use a sessão da conta ou o convidado edm_…." is an authentication hint rather than usage guidance. It never states when to call this instead of buscar_empresa, selecionar_empresa, or listar siblings, nor any prerequisite or exclusion.

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