Check in guests

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

Goes well beyond the annotations by disclosing that guests receive no message (no notification side-effect), that ids not on the guest list are refused (error behavior), that only hosts may call it (auth requirement), and what the response summarizes. These are exactly the mutation details annotations cannot convey.

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?

The primary action is in the first sentence, with undo second and edge-case/return details following in short, dense sentences. No filler or repetition of the title.

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 non-destructive, non-idempotent mutation with no output schema, the description covers side effects, permissions, error handling, and return shape — everything an agent needs to invoke it 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?

Schema coverage is 100%, so event_id, guest_ids, and undo are already fully documented, and the description mostly restates them. It adds only the refusal rule for unknown ids, which is marginal over the schema baseline.

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 guests as checked in at the door') plus the inverse operation ('undo it'), which is unambiguous against siblings like approve_guests and invite_guests. An agent can tell this is the door check-in action, not the invite/approve flow.

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?

Explains the undo path and the 'Hosts only' permission gate, and notes that non-guest ids are refused, giving clear conditions for use. It does not explicitly contrast with approve_guests or invite_guests, so the sibling differentiation is inferred rather than stated.

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