invite_guest_to_event

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

Annotations already declare idempotentHint, destructiveHint=false, and openWorldHint, so the safety profile is covered. The description adds meaningful scope behavior beyond those flags: the operation is additive and does not affect other events. Its 'Idempotent' sentence largely restates the annotation rather than extending it.

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?

Three tight sentences with zero filler; the additive scope is front-loaded and the parameter rule follows immediately. Every sentence 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?

For a three-parameter mutation with full schema coverage and annotations covering safety, the description supplies everything needed to call it correctly: scope, exclusivity rule, and idempotency. No output schema exists, so no return-value explanation is required.

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%, so each parameter is already documented, establishing a baseline of 3. The description adds value beyond the schema by stating the XOR constraint (exactly one of guest_group_id/guest_id) and clarifying that each option maps to a different invitation scope.

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 and resource ('Invite a single guest or guest group to an event') and pins down the scope with 'additive — does not affect other events.' This distinguishes it from nearby siblings like set_event_guests and remove_event_invitation without needing to open their schemas.

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?

Gives the key selection rule — 'Pass exactly one of guest_group_id ... or guest_id' — so the agent knows the two parameters are mutually exclusive. It does not explicitly name an alternative tool or a when-not condition, but the additive framing supplies clear usage context.

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