send_contact_message

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

No annotations are provided, so the description bears the full burden of behavioral disclosure. It mentions sending via the Zappaz API but does not describe side effects, authentication requirements, rate limits, or the fact that this is a write/mutation operation beyond what the verb 'Envia' already implies.

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 a single, front-loaded sentence with no wasted words. The trailing phrase 'atraves da Zappaz API' is arguably filler since all sibling tools share that API, but the overall structure is concise and easy to parse.

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?

For a tool with a required nested object, no output schema, and no annotations, the description is too sparse. It does not explain how to structure the data parameter, what the contact object requires, or any usage conditions. An agent must rely almost entirely on the input schema to call it correctly.

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 for the top-level parameter is 0% (the only parameter 'data' has no description in the schema). The description adds no information about the required structure of data, such as the need for number and contact fields. Although nested fields have schema descriptions, the description itself does nothing to compensate for the undocumented top-level parameter.

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 (Envia) and resource (mensagem com um contato), and the phrase 'com um contato' distinguishes it from the other send_*_message siblings that send text, image, video, etc. However, it remains slightly ambiguous whether the contact is the payload or the recipient, which prevents a top score.

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?

No when-to-use guidance is given. The description does not say when to choose this tool over send_text_message, send_image_message, or any other sibling, nor does it name prerequisites or exclusions. It only states what the tool does.

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