invite_guest_to_event

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

Adds 'additive — does not affect other events' and 'Idempotent' beyond annotations (only destructiveHint: false). These are key behavioral traits for a mutation tool, though it lacks details on side effects or failure modes.

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 efficient sentences front-load purpose and key characteristics, with no wasted words. Instruction on param usage is direct.

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 simple mutation tool with 3 params, no output schema, and minimal annotations, the description covers purpose, param usage, and idempotency. Could mention return value or prerequisite (guest/group exists), but overall adequate.

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% (baseline 3), but description adds value by clarifying mutual exclusivity and explaining the effect of each optional parameter ('invites just that guest' vs 'invites every guest in the group').

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?

Description clearly states the action ('Invite a single guest or guest group to an event'), specifies the resource, and distinguishes from siblings like add_guest (add guest to list) and remove_event_invitation.

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?

Explicitly instructs to pass exactly one of guest_id or guest_group_id, mentions idempotency, and implies when to use. Does not explicitly state when not to use, but context with siblings provides clarity.

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