update_group_picture

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

With no annotations, the description must carry the full behavioral burden. It uses 'Atualiza' (updates), implying mutation, but doesn't state whether it requires admin permissions, whether the change is reversible, what happens to the old picture, or what the response looks like. This is significantly under-specified for a mutation tool.

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 concise sentence that front-loads the action and resource. It is efficient, though its brevity borders on under-specification given the lack of behavioral or parameter detail.

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 mutation tool with no annotations, no output schema, and a nested object parameter, the description is too sparse. It omits required behavioral context (auth, side effects) and parameter details, leaving the agent with insufficient information to invoke it confidently.

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 reported as 0% at the top level, but the nested object properties include Portuguese descriptions for both 'source' and 'identifier'. The top-level parameter 'data' is not described in the schema, and the tool description adds no parameter information. The nested descriptions partially compensate, yielding a marginal score.

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 Portuguese description states a specific verb+resource: updating a group's profile picture on the Zappaz API. It clearly maps to the update_group_picture tool name. However, it does not distinguish this from siblings like update_group or send_image_message, which an agent might confuse when choosing a picture-related operation.

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 guidance is provided on when to use this tool versus alternatives like update_group or send_image_message. The description does not mention prerequisites, permissions, or conditions that would help the agent select it correctly.

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