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

Annotations declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, destructiveHint=false, so the safety profile is already covered. The description adds the useful behavioral fact that this governs where NEW bookings are written, implying existing bookings are unaffected, but it says nothing about per-user vs. per-team scope, whether unsetting is possible, or what happens to the previous destination.

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 waste. It is efficient, though the terseness leaves no room for the parameter or scope detail an agent needs.

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?

A mutating, non-idempotent setting change with three undocumented parameters and no output schema. The description should explain how to obtain externalId, what delegationCredentialId does, and whether the setting is user- or team-scoped; none of that is present.

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 0% for all three parameters. The description does not explain externalId (a calendar identifier from an integration), the integration enum values, or what delegationCredentialId is for — arguably the most opaque parameter. It only vaguely gestures at 'a calendar'.

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 ('Choose') and resource ('the calendar that new bookings are written to'), making the effect on future bookings clear. It does not distinguish itself from nearby siblings like select_calendar, unselect_calendar, or set_default_conferencing, so an agent must infer the difference.

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 guidance on when to use this versus select_calendar (which likely controls conflict-checking calendars) or set_destination_reminder. No prerequisites are mentioned, such as whether the calendar must already be connected via connect_calendar_with_credentials.

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