lookup_ddd

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

No annotations provided. Description discloses it is online and cached, but lacks details on rate limits, authentication, handling of invalid DDDs, or whether it requires internet connectivity. The caching info is useful but incomplete for full transparency.

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?

Two concise sentences. First states purpose, second adds caching detail. No extraneous words. Efficiently communicates core information.

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 (one parameter, output schema exists), the description covers the main purpose and a performance characteristic (caching). Lacks mention of error conditions or return format, but output schema fills some gaps. Adequate for the complexity level.

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 has no parameter descriptions (0% coverage). The description adds that DDD must be a 2-digit code, which gives meaning beyond the schema's string type. This helps the agent format the parameter correctly.

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?

Description clearly states 'Consulta UF e lista de municípios por código DDD' — verb (Consulta) and resource (UF and municipalities by DDD). Distinguishes from sibling tools like lookup_cep and lookup_ibge_municipio which serve different lookup purposes.

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?

Implies online usage via BrasilAPI and mentions 90-day caching, which helps in deciding when to call. However, does not explicitly state when not to use or compare with alternatives. Given the tool's specificity, it's still clear.

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