indico_set_checkin

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the mutation/safety profile is covered structurally. The description adds one genuinely useful behavioral fact beyond the annotations: the operation is reversible ('or undo it'), which matters for a toggle tool. It says nothing about required permissions or what happens if the registrant is already in the target state.

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?

A single short sentence, front-loaded with the action and resource, with the toggle behavior appended without waste. Nothing here needs trimming.

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 values need no explanation, which the description correctly omits. However, for a mutation tool with 40% parameter coverage and no usage guidance, the description is thinner than the tool's complexity warrants; it leaves the agent to infer which ids identify the target registration and under what conditions check-in is allowed.

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 only 40%: event_id and instance carry descriptions, but form_id, registration_id, and checked_in are bare titles, and the description adds no parameter-level information whatsoever. With three of five parameters undocumented anywhere and low overall coverage, the description fails to compensate for the schema gap.

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: 'Mark a registrant as checked in at the venue, or undo it.' The toggle semantics are clear from the single sentence, so an agent knows exactly what state change occurs. It does not explicitly distinguish itself from the closest sibling, indico_moderate_registration, which is the only thing keeping it from a 5.

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?

Usage is only implied: the 'or undo it' phrasing signals this is a state toggle rather than a one-way action, so an agent can infer when to call it. There is no explicit when-to-use guidance, no mention of prerequisites such as the registration needing to be confirmed, and no routing away from related tools like indico_get_registration or indico_moderate_registration.

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