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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real value by enumerating what the response contains (fiscal data, QSA partners, linked contacts), but says nothing about errors when the id is unknown or about completeness of the returned records.

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 sentence with zero filler, front-loading the action and resource and then appending the scope of returned data. Nothing in it is redundant with the title beyond the unavoidable name/verb overlap.

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 read-only single-parameter getter with full schema coverage and no output schema, the description supplies the missing return-content summary, which is the main gap an agent would otherwise have. It is nearly complete; only failure/empty-result behavior is left unstated.

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?

Only one parameter and schema coverage is 100% — the schema already explains that company_id is a string obtained from list_companies. The description merely repeats "pelo id" without adding format, validation, or example detail, so baseline 3 applies.

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 ("Detalha") and resource ("empresa") plus the fields it surfaces (dados fiscais, QSA, contatos vinculados). This distinguishes it from write siblings such as create_company or enrich_company, though it never explicitly contrasts with list_companies.

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 when-to-use or when-not-to-use guidance and names no alternatives. The only routing hint ("ID obtido via list_companies") lives in the schema, not the description, and sibling alternatives like get_contact_360 or enrich_company are never mentioned.

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