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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the safety profile is covered. The description adds no behavioral context beyond that: it does not say whether omitted fields are cleared or left untouched, whether attendees are replaced or merged, or whether attendees get notified — all material for a destructive calendar mutation.

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 front-loaded sentence with no filler or redundancy. Its brevity is efficient, though it comes partly at the cost of the missing detail noted above.

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 nine-parameter destructive mutation with no output schema and an ambiguous near-twin sibling, the description is too thin. It omits update semantics (partial vs full replacement), format expectations for start/end, and any guidance on disambiguating from the calendar-event variant.

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 33%, so the description is expected to compensate, and it does name four of the nine parameters (title, time, attendees, status). But it adds no format or behavior detail — start/end string formats, attendee replacement semantics, and whether 'status' is an RSVP or a cancellation remain 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?

The description gives a clear verb ('Change') and resource ('an event on a connected calendar') and enumerates the mutable fields, so the operation is understandable. However, it does nothing to distinguish this from the sibling 'update_calendar_event', leaving the connection-vs-calendar distinction unaddressed.

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?

There is no when-to-use guidance, no when-not-to-use guidance, and no named alternative. An agent facing both 'update_connection_event' and 'update_calendar_event' gets no help choosing; the only prerequisite hints (IDs from list_connection_events and list_calendar_connections) live in the schema, not the description.

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