add_participants

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

With no annotations, the description carries the full burden, yet it only implies a mutation via 'Adiciona' and discloses nothing else: no permission requirements, no behavior for already-present participants, no error conditions, and no indication of whether the array is additive or replacing.

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?

It is a single front-loaded sentence with no padding, which is structurally clean. The brevity is driven by under-specification rather than efficiency, so it earns only a middling score.

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 mutating, two-required-parameter tool with zero schema documentation, no annotations, no output schema, and a dense set of closely related sibling tools, this one-liner omits far too much. An agent cannot reliably call it without guessing the identifier format and the effect on existing members.

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 coverage is 0% and neither parameter has a description, so the description must compensate — but it does not. It never clarifies what the string items in 'data' represent (phone numbers, user IDs, participant identifiers) or that groupId identifies the target group, leaving both required parameters semantically opaque.

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 a specific verb and resource ('Adiciona participantes a um grupo'), which is enough to distinguish it from siblings like remove_participants or create_group. However, it makes no explicit reference to any alternative tool and the trailing 'na Zappaz API' adds no distinguishing information.

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?

There is no guidance on when to use this tool versus remove_participants, promote_participants, or create_group, nor any noted preconditions (e.g. group must exist, participants must not already be members). The agent must infer everything from the name.

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