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

With no annotations, the description carries the full burden and discloses several behavioral traits: it is a read-only operation ('Looking does not join'), it specifies error behavior for bad invite codes (404 `not_found`), and it states billing ('1 Credits' per call). It does not mention authentication requirements or rate limits, but the core side-effect and error semantics are well covered.

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 front-loaded with what data is returned, then adds usage, error, and billing notes. It is a single dense sentence for the return fields, but every detail is useful because there is no output schema to document the returned structure.

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?

Given that the tool has no output schema, the description fully compensates by enumerating the returned fields (group name, description, size, creation time, settings, owner, participants). It also covers the non-joining behavior, error response for invalid codes, and billing, leaving no meaningful gap for an agent 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 is 100%, so the `code` parameter is fully documented in the schema itself. The description adds no additional syntax or format details beyond what the schema already provides, making the baseline score of 3 appropriate.

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 resource and operation: it returns what WhatsApp shows anyone who opens a group's invite link — group name, description, size, creation time, settings, owner, and participants. It is clearly distinguishable from siblings like get_v1_channel or get_v1_number_profile because it targets group invite links specifically.

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?

It gives clear context — 'Looking does not join the group' — which tells the agent this is a non-joining preview operation. It does not explicitly name alternatives or when-not-to-use conditions, but the sibling tools are unrelated enough that no exclusion is needed.

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