Create Calendar

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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true), so the bar is lower. The description still adds real value by disclosing the permission requirement and the negative side effects (no invitations, no email reminders), which an agent needs before committing a create.

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?

Three short sentences, each doing distinct work: guardrail, permission, side-effect exclusion. Front-loaded with the action and the condition, with zero filler.

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?

An output schema exists, so return values need no explanation, and for a simple two-required-parameter create the description covers the essentials: scope, permission, and what does not happen. Only the multi-mailbox/mailbox_id context is left entirely to the schema.

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%, including the mailbox_id targeting rule and the Idempotency-Key replay semantics, so the schema carries parameter meaning. The description adds nothing about name, time_zone, or multi-mailbox targeting, leaving this at the baseline for a fully documented schema.

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 ('Create a private calendar'), and the 'private' qualifier plus the no-invitations note separates it from event-creation siblings like mailbox_create_calendar_event. It does not name a sibling directly, but the resource boundary (calendar vs. event) is unambiguous.

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?

Gives an explicit gating condition ('only when the user asks') and the required scope ('Requires calendar.write'), which tells the agent both when to call and what permission precondition must hold. No explicit mention of list_calendars for checking existing calendars first, which is the main missing routing hint.

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