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

Annotations already indicate the tool is read-only, idempotent, and non-destructive. The description adds that the tool returns IBGE codes and includes a data license note, but does not disclose behavior like pagination hints, rate limits, or response ordering. Overall, it provides moderate added value beyond annotations.

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?

The description is two sentences that efficiently state the purpose and scope, with the licensing info appended. It is front-loaded with the core action. While very concise, the license line could be considered secondary, but overall no wasted words.

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?

Given the tool's simplicity (optional filter, no required params, read-only, output schema present), the description covers the essential purpose and filter option. It does not detail error handling or ordering, but for a list tool with full annotations and a rich output schema, this is reasonably complete.

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 100%, so baseline is 3. The description mentions filtering by state code and alludes to the limit parameter indirectly through the 'all 5,570' phrasing, but does not add significant meaning beyond the schema's own parameter descriptions. Returns are adequately explained via the output schema.

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?

The description clearly states the tool lists all 5,570 Brazilian municipalities with IBGE codes, and mentions optional filtering by state code. This is a specific verb+resource combination that distinguishes it from sibling IBGE tools like gov.ibge.states or gov.ibge.cnae.

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 implies usage for listing municipalities, with an optional filter by state code, but does not explicitly discuss when to use this tool versus alternatives like gov.ibge.regions or gov.ibge.states. No 'when not to use' guidance is provided.

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