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

Annotations already state readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is clear. The description adds a note about bulk support via 'ids', which is useful. It does not mention errors, rate limits, or what happens on invalid ids, but given the annotations cover the main behavioral traits, this is acceptable.

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 very short, two sentences, and front-loaded with the primary purpose. The bulk support note is concise and relevant. No fluff. It earns a high score for efficiency.

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?

The tool has 3 parameters, one required, and no output schema. With annotations providing safety info, the description does not need to explain return values, but it should clarify the optional 'ids' and 'account' parameters. The current description only hints at bulk via 'ids', leaving 'account' unexplained. Given the simplicity of the operation (fetch by id), it is fairly complete, but the gap on parameters and no guidance on fallback or error handling suggests a slightly below-average score.

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 0%, meaning the description does not explain any parameters. The schema itself defines 'id' and 'ids' (with anyOf types) and 'account', but the description only mentions 'id' and 'ids' indirectly via bulk support. The description adds minimal value beyond the schema: it doesn't explain that 'account' might be needed or what formats are expected. Since there is 0% coverage, the description should compensate, but it does not, so a low score is warranted.

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 states it retrieves a contact by id, which is a clear verb+resource. However, it does not explicitly distinguish from sibling tools like tiny_list_contacts (which lists contacts) or tiny_create_contact, though the 'Detalha um contato' (details a contact) implies a single-item fetch. It lacks a clear statement that this is for fetching a single contact vs a list, so it is adequate but not exemplary.

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 mentions bulk support for batched execution via 'ids', which gives some usage context. However, it does not provide explicit guidance on when to use this tool versus alternatives like tiny_list_contacts when you need multiple contacts, or tiny_get_contact for a single contact. No exclusions or alternative recommendations are given, so it's clear but minimal.

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