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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantive context beyond them: it reports the plan, per-table row estimates, and the concrete 5-million-row rejection threshold. It doesn't detail output shape, but the safety and limit profile is well covered.

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?

One front-loaded sentence that leads with the relationship to the sibling, then enumerates the three outputs. No filler.

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 validation tool with no output schema, the description explains what is returned (validation result, plan, row estimates, rejection verdict) and the governing limit. The only gap is the unexplained 'ano' parameter.

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% for both parameters. The description implicitly maps to 'sql' ('valida o SELECT'), but the 'ano' parameter is never mentioned, so half the inputs remain undocumented in both schema and description.

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 action (dry-run/estimate of a SQL query) and explicitly frames itself as the non-executing variant of eleicoes_consulta_sql. An agent can immediately distinguish it from the executing sibling.

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 phrase 'Só o pré-voo da eleicoes_consulta_sql, sem executar' names the alternative and the condition that selects it (validation without execution). It stops short of an explicit 'use this before running any query' imperative, but the routing is clear.

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