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

Annotations already establish read-only, idempotent, non-destructive and closed-world, so the description is not carrying the safety burden. It adds real context beyond them: a fixed, small result set of 33 rows with named fields, explicit units (R$ bilhões, milhões) and the 'último ano disponível' qualifier on the growth figure.

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 sentence, front-loaded with the resource and row count, then the breakdown, then the returned fields. No filler or restatement of the title.

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?

There is no output schema, so the description has to describe the return payload — and it enumerates every field with units and the freshness caveat on growth. For a no-parameter list tool this is 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?

The tool takes zero parameters, so the baseline is 4. The description correctly adds nothing about inputs and instead invests its space in describing outputs, which is the right allocation here.

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 ('Lista os 33 territórios'), plus the exact scope (Brazil, 5 regions, 27 UFs) and the fields returned. It implicitly separates itself from get_territory_profile by being the full enumeration, but never names that sibling or states the division of labor explicitly.

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 fixed count of 33 and the summary indicators signal 'call this to get the whole territory catalogue'. There is no explicit when-to-use, no exclusion, and no pointer to get_territory_profile for per-territory detail.

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