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

The annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=true; the description's 'WRITE:' prefix and PUT verb are consistent with them but largely restate that. It adds nothing about the destructive implication — that an existing attendance record is overwritten — nor about prerequisites such as the guest/contact needing to exist.

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 clauses: the 'WRITE:' marker and the action lead, followed by values and endpoint. Every element earns its place and nothing is buried.

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 three-parameter mutation with full annotation coverage and no output schema, the description covers intent and legal values. It still omits what the call returns and whether prior attendance data is lost, which matters given destructiveHint=true.

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 67% and both id parameters are well documented there. The description repeats the post_status enum values without adding format or constraint detail, and does not clarify the `ext:` id form or what UNKNOWN means versus clearing the status.

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?

A specific verb (set) plus resource (guest attendance/post status), with the three legal values spelled out and the underlying endpoint named. It usefully disambiguates 'post' as attendance rather than HTTP POST, but it never explains how this differs from the sibling evenium_update_guest_status, which an agent could easily confuse with it.

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 parenthetical 'for example after check-in' gives a concrete usage context, but there is no explicit when-not guidance and no mention of evenium_get_guest_post_status for reading the current value or evenium_update_guest_status as the alternative. Usage is implied rather than routed.

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