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

Annotations already declare readOnly, non-destructive, idempotent, closed-world. The description adds real behavioral context beyond that: it only compares data as returned by prior queries in this account, and it does not assume policy or validity. That is a meaningful disclosure of what the tool does not do. It stops short of explaining limits (e.g., 50-item cap, what happens with expired references), so a 4 rather than 5.

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, no filler, and the key scoping constraint (same account, as-returned data) is front-loaded. Every clause earns its place; nothing redundant with the schema or annotations is repeated.

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?

With read-only annotations and no output schema, the description need not explain return shape. But for a tool whose only input is an opaque reference structure at 0% schema coverage, the missing explanation of what references must contain is a real completeness gap an agent will hit immediately.

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 coverage is 0% for the single 'referencias' parameter, so the schema carries no descriptive text. The description never explains what a referencia is, that it needs resultadoId + caminho, or the 50-item bound. For a parameter with zero coverage the description should compensate and it does not.

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 (compara) and resource (preço, moeda, condições e disponibilidade) with clear scope: comparisons of options returned by prior queries in this same account. It distinguishes itself from siblings like gover_consultar_resultados_voos or gover_buscar_voos by being comparative rather than a lookup. But it never names the alternatives (e.g., gover_solicitar_comparativo_precos, gover_consultar_status_comparativo), leaving the sibling separation implicit.

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 sentence 'exatamente como retornados nas consultas desta mesma conta' implies you must have run queries first, giving an implicit precondition. It does not state when to prefer this tool over the several comparison-related siblings or what happens if references are stale. Adequate but no explicit when/not/alternatives.

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