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

Beyond the annotations (which declare destructive and non-idempotent), the description discloses the 7-day link validity, join-on-accept behavior, replacement of the prior open invitation, the 409 already_member outcome, and a concrete rate limit (10 req/min shared with WhatsApp template/broadcast endpoints). This is unusually rich behavioral context not derivable from structured fields.

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?

Front-loaded with the action, then the behavioral details, and the rate-limit note is legible. The leading line duplicates the title/verbatim action, a minor waste, but the rest earns its place.

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?

With no output schema, a description for a mutation tool should ideally say what the call returns (e.g. the created invitation), which is absent. Otherwise it is complete: role semantics, agent scoping, error cases, expiry, and rate limits are all covered.

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 100% and the property descriptions already explain role, email, agent_ids, and all_agents in detail. The description largely restates that (e.g. 'required then; with every agent they are refused'), adding little semantics beyond the schema, so the baseline 3 applies.

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 (invite a person by email as a given role) and names the scoping target (all agents or agent_ids). It's clear what the tool does, but it never names an alternative sibling to route to — resend_invitation and cancel_invitation appear only in passing, so sibling differentiation is not explicit.

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 only implied: the description covers the already-member case (409) and replacement of an open invitation, and mentions resendInvitation, but it never states 'use this when X, use resend_invitation when Y'. An agent must infer the routing rather than being told it.

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