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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds substantive context beyond that: the payload contains column semantics, worked example queries, and sha256 provenance of source files, which tells an agent why calling it first pays off.

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 compact sentence that front-loads the resource and ends with the routing instruction. Dense and waste-free, though the parenthetical table list is heavy relative to the rest.

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 no output schema, the description does the work of describing the return payload (table/column meanings, example queries, source hashes). Only the unexplained 'ano' parameter leaves an unresolved question for an otherwise simple, annotation-covered read tool.

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 single optional parameter 'ano' has 0% schema description coverage and is never mentioned in the description. An agent cannot tell whether it filters the returned schema metadata, selects a specific election year's dataset, or is ignored — this is the definition's clearest gap.

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 resource (public tables and columns of the MCP's SQL database) and enumerates the tables by name (secoes, municipios, totais_municipio, candidatos, votos_por_minuto, fontes), plus what else is returned: column meanings, 5 example queries, and TSE source file hashes. This is clearly distinguishable from the query-execution siblings.

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?

Explicitly instructs 'Chame antes de eleicoes_consulta_sql', giving a clear prerequisite ordering against the main alternative. No mention of when NOT to use it (e.g., for coverage questions or printed-ballot checks), so it stops short of 5.

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