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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value by disclosing bulk execution capability ('accepts ids for batched execution'), which is not captured in annotations and is useful for the agent. It does not contradict 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 extremely concise: two sentences, front-loaded with the main purpose and then the bulk note. Every word earns its place, with no redundancy or filler. Ideal structure for quick parsing.

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?

Despite being a get-by-ID tool, the presence of a 'query' parameter adds complexity that the description does not address. There is no output schema, so the agent does not know what 'dados completos' includes. The bulk support note lacks details (e.g., limits, format of ids). The description is too sparse for a tool with three parameters including an object.

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?

With 0% schema description coverage, the description must compensate for the parameters. It partially explains 'id' (single lookup) and 'ids' (bulk), but completely ignores the 'query' object parameter, which is a significant gap. The agent cannot infer what 'query' expects or how it relates to the other parameters.

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 retrieves complete contact data by ID, with a specific verb ('Busca') and resource ('dados completos de um contato por ID'). It distinguishes itself from sibling tools like advbox_list_customers (which likely lists many) and advbox_customers_birthdays, making its purpose unambiguous.

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 fetching a contact by ID, and the mention of bulk support suggests using it when multiple IDs are available. However, it does not explicitly state when to prefer this over alternatives like advbox_list_customers or exclude cases (e.g., when only partial data is needed). Guidance is present but not fully articulated.

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