List Calendar Events

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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the bar is lower; the description still adds real value by disclosing the required calendar.read scope and the eventual-consistency trait of UID search. The warning that an empty lookup leaves an uncertain create unresolved and must not be retried is exactly the kind of behavioral context annotations cannot convey.

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, front-loaded with purpose, followed by the auth requirement and the consistency caveat in priority order. Slightly hurt by the awkward phrasing 'never authorises repeating it', which a reader has to parse before understanding the retry prohibition.

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?

With annotations declaring the safety profile, an output schema covering return values, and full schema parameter descriptions, the remaining burden is auth and consistency semantics — both are stated. An agent can select and invoke this tool correctly without further inference.

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%, so every parameter (uid, limit, cursor, mailbox_id, calendar_id) is already documented in the schema, including the mailbox_id omit-when-single-mailbox rule. The description only restates the UID lookup mode and adds no syntax, range, or interaction detail beyond the schema, so the baseline 3 applies.

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 ('List events in the selected mailbox') and adds a second mode ('look up a caller-held UID'), so the agent knows this tool both enumerates and fetches by UID. It stops short of naming the closest sibling (mailbox_get_calendar_event) which appears to be the dedicated single-event fetch, leaving the mode overlap unresolved.

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?

'Requires calendar.read' gives a clear prerequisite, and the two operating modes imply when the uid parameter path applies. However, there is no explicit when-to-use versus mailbox_get_calendar_event or mailbox_get_calendar_event_changes, and no guidance on when to paginate through the full mailbox listing versus targeting a UID.

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