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

Annotations only set destructiveHint=false, while the description adds the login/organizer requirement, confirmed=false default hiding from the public page, avatar self-service, a per-event limit of 30, and the fact that this tool does not notify. These are exactly the mutation and side-effect details an agent needs.

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?

Dense but front-loaded: login/organizer and 'only add' come first, followed by conditional visibility, capacity, and notification caveat. Every clause carries operational meaning; nothing is padded.

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 6-param mutation with a rich input schema and only destructiveHint=false, the description supplies auth, visibility, capacity, duplicate handling, and notification boundaries. No output schema exists, but the description gives enough to call the tool 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?

All six parameters already have schema descriptions at 100% coverage, including the confirmed and userId semantics that the description largely repeats. The description adds a per-event limit and avatar note but no new parameter-level syntax beyond the schema, so baseline 3 is 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 opens with '只新增嘉宾' (only adds a guest) and scopes it to logged-in organizers, then separates it from status changes and invite-link sending. The resource and scope are clear from the guest/activity context, and it explicitly says not to use it for existing guest status changes.

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 states the organizer/login precondition, says not to use it for existing guestId duplication or status changes, and routes notification to create_guest_invite_link. It lacks an explicit instruction to check list_activity_guests first or how it relates to add_guest_candidates.

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