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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so the safety profile is covered. The description adds genuine non-obvious context: the token is single-use and no email is dispatched, which explains the non-idempotent and 'destructive' character.

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?

Two punchy sentences, front-loaded with the core action and scope, then the critical behavioral caveat. No filler.

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?

An output schema exists so return shape need not be described, and the destructive/non-idempotent traits are disclosed across annotations and description. Only the participantId meaning is left to the schema, a minor gap for a two-param tool.

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 0%, so the description must carry the load, and it does partially: it labels id as the 'trip uuid', clarifying that the generic uuid is a trip identifier. It leaves participantId as a bare uuid label, so it compensates but not fully.

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 (generate/return), the exact resource (SINGLE-USE invite token), and the target scope (an existing participant). An agent can distinguish this from add_trip_participant and remove_trip_participant without opening the 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?

The explicit exclusion 'Does NOT SEND an email -- you share the link yourself' tells the agent what this tool will not do, which prevents a common misuse. It stops short of naming the sibling (add_trip_participant) as the alternative when adding a brand-new participant.

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