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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile needs no restating. The description does add genuinely useful behavior: hard caps of 20 addresses and 20 companies, and that `pontos_total` carries the true total. It stops short of saying what happens on an invalid CEP or whether the truncated result means a follow-up call is needed.

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?

Three short clauses, each carrying distinct information (what it returns, the result caps, the cost profile), with the payload statement front-loaded. Slightly compressed to the point of dropping the verb in the opening clause.

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?

No output schema exists, so the description correctly takes on return-value disclosure: it names addresses, companies, limits, and the `pontos_total` counter, and states the tool is free. A one-clause note on invalid-format CEPs or empty results is the only real gap.

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?

Only one parameter and schema coverage is 100%, with the '8 digits' format documented in the schema itself. The description adds nothing about the CEP parameter, 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 resource and verb: returns addresses at a CEP plus the companies registered there, with coordinates from CNEFE/IBGE. It is clearly distinguishable from consulta_cnpj-style lookups, though it never names the closest sibling (consulta_endereco) to draw the line 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 implied rather than stated: an agent can infer 'use this to look up a CEP', and the cost note ('free: uses no daily allowance or balance') gives a real reason to prefer it over paid siblings. But there is no explicit when-not and no comparison against consulta_endereco or consulta_cnpj.

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