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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the set of returned attributes (paid state, attended), which is useful given no output schema, but discloses nothing about permissions, pagination behavior, or result volume.

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 tight sentences with the resource and returned fields front-loaded, followed by the filter axes. The trailing 'GET /eventAttendee' is mildly redundant with the endpoint context but harmless.

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?

With no output schema, the description usefully enumerates the fields an attendee record carries, and the schema covers pagination and filters. Complete enough to call correctly, though it omits any note on default ordering or result size.

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 100%, so the schema already documents limit, fields, offset and the three id filters. The description's 'filter by event, member or guest' merely restates the event_id/member_id/guest_id parameters without adding format or combination semantics; baseline 3 applies.

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 ('List who is signed up to events') and enumerates the returned data (member/guest, event, sign-up date, paid state, attendance). It is clearly distinct from list_check_ins and list_events, though it never names a sibling explicitly.

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?

'Filter by event, member or guest' gives the supported filtering axes, which implies usage, but there is no guidance on when to choose this over list_check_ins or get_event, and no exclusions or prerequisites.

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