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

Annotations already disclose destructiveHint=true and non-idempotency, but the description adds the crucial side effect that prior links are revoked — the most important behavioral fact for an agent deciding whether to call this. It does not mention expiry, permissions, or link format, keeping it from a 5.

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?

A single front-loaded sentence with no filler; the destructive revocation caveat is placed immediately after the purpose, exactly where an agent needs it.

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 destructive mutation with no output schema, the description covers the essential fact (old link is revoked) and the annotations cover the safety profile, so an agent can call it correctly. It omits who can perform the action and whether the new link replaces or coexists with others, which would round it out.

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 67%: profile_id and phone_number_id are documented, but group_id has no schema description, and the tool description supplies nothing about any parameter. With partial coverage the description should compensate for the undocumented parameter, and it does not.

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 ('Generate a fresh invite link for a WhatsApp group'), which clearly separates it from siblings like whatsapp_group_create or whatsapp_group_update. It does not name a sibling explicitly, so it stops short of a 5.

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?

Usage is implied rather than stated: an agent can infer this is the tool for producing an invite link, but there is no explicit when-to-use guidance, no prerequisites (e.g. admin rights), and no routing to an alternative such as whatsapp_group_join_requests_list for seeing who wants in.

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