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

With no annotations, the description carries the full burden: it implies a read-only lookup but says nothing about permissions, pagination caps, or behavior when both CNPJ and CNES are supplied or when neither is. The existence of a `limite` parameter with a default and maximum hints at truncation behavior that is never disclosed.

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 short sentences, front-loaded with the purpose and followed by a use/don't-use delimiter that maps directly to agent decision points. 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?

An output schema exists, so return-value detail is not owed here. However, for a three-parameter lookup with zero schema descriptions, leaving `limite` and the both-optional key ambiguity unexplained means an agent can invoke it but may misuse the parameters.

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%, so the description must compensate. It names CNPJ and CNES as the lookup keys but gives no format guidance (digits only vs. punctuation), no statement that at least one key is required, and never mentions the `limite` parameter at all.

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 and resource ("Consulta as operadoras vinculadas a um CNPJ ou CNES") and immediately frames the scope as vínculos of an establishment. It also explicitly separates itself from the sibling operadora_lookup, so an agent can route without opening any schema.

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?

Uses explicit when-to-use / when-not-to-use clauses and names the alternative tool (operadora_lookup) for the excluded case. This is the strongest possible routing guidance in a single sentence pair.

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