Invite members by email

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

Annotations already flag destructiveHint=true, openWorldHint=true, and idempotentHint=false, so the safety burden is partly covered; the description adds real context the annotations cannot, namely that an invitation email is actually sent externally, that existing group members are silently skipped, and that acceptance bypasses approval. It never explains why this is 'destructive' (are invites revocable? does it consume seats?) nor any rate limits, which matters for a 50-address batch.

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?

'Admins only' appears twice, wasting a sentence, and the phrase 'as Invite people, Invite by email does' is garbled and costs the reader a pass to parse. The useful scope statement (no membership request, external recipients) is present but not front-loaded ahead of the duplication.

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, the description should say what a batch call returns — per-address success, skipped-existing, or invalid — which is important when up to 50 emails are submitted at once. Permissions and side effects are covered adequately, but the outcome shape is left entirely to inference.

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 group, emails, and course_ids are already documented in the schema, including the 50-address cap and the course-id hint. The description adds no format or semantic detail beyond what the schema states, which is the expected baseline behavior.

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?

States a specific verb+resource (email an invitation to members) and pins down the distinguishing effect: recipients join directly without a membership request, which separates it from approve_membership_request. It also clarifies that the emails go to people outside the group, distinguishing it from send_message.

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?

'Admins only' sets a clear precondition, and 'whoever accepts joins without a membership request' tells the agent this is a pre-emptive path rather than a request-handling one. It never explicitly names a sibling tool as the alternative, so the routing is implied rather than stated.

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