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

Annotations already declare destructiveHint=true and openWorldHint=true; the description adds real side-effect detail beyond that: event times are preserved and guests receive an email update. It still doesn't say whether the event is removed from the source calendar or what the response contains, but the guest-notification disclosure is genuinely useful.

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 compact sentences, with the core action and result front-loaded and the side-effect caveat following. No filler or redundancy.

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 mutation tool with no output schema, the description covers the key behavioral facts an agent needs before invoking it: scope, time preservation, and guest notification. Only the missing parameter detail and the fate of the event on the source calendar keep it from being fully complete.

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 only 50%: mailbox and calendarId are documented, while eventId and destinationCalendarId carry no descriptions. The prose mentions moving 'an event' and 'a different calendar' generically but adds no format, ID-source, or identification guidance to compensate, leaving two parameters effectively undocumented.

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?

Clear specific verb and resource: moving a calendar event to a different calendar while preserving its times. It also scopes the operation ('same account'), which rules out cross-account transfers. It does not explicitly name siblings like update_google_calendar_event, so an agent must infer the distinction.

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 description conveys the implied use case (relocating an event between calendars) but offers no explicit when-not guidance and never names the alternative move_outlook_calendar_event or update_google_calendar_event, which is the tool an agent might reach for when only the time changes.

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