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

No annotations are supplied, so the description carries the disclosure burden. It does add real value by naming the return fields and flagging that the call is free, but it says nothing about partial-match behavior, result caps, pagination, or what happens when no município matches.

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 with the action first and the returned fields after; nothing is redundant or padded.

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 one-parameter lookup with no output schema, the description adequately covers what comes back (IBGE code, UF, emendas total) and the cost model. Only edge-case behavior — no matches, many matches, result limits — is left uncovered.

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 100% and there is only one parameter, whose description already defines it as a name or name fragment. The prose adds no format, accent/case-handling, or minimum-length guidance beyond the schema, so the 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 and resource ("Encontra municípios"), the lookup key ("pelo nome"), and the exact payload returned (código IBGE, UF, total de emendas). It does not differentiate itself from siblings like resumo_municipio or ranking_municipios, so an agent must infer that this is the name-based lookup vs. the detail/ranking tools.

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?

Usage is only implied: the tool takes a name fragment, and "(gratuito)" hints that it works without the paid access granted by ativar_acesso/comprar_acesso. There is no explicit statement of when to pick this over resumo_municipio (which presumably gives per-municipality detail) or any exclusion.

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