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

Annotations already establish readOnly, idempotent, non-destructive, so the safety profile needs no repeating. The description earns credit for adding genuinely new behavioral context beyond the annotations: a hard 62-day maximum window and a UTC normalization rule. It stops short of covering pagination, result caps, or ordering.

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?

One dense front-loaded sentence carries the constraints and returned fields efficiently, but the trailing 'Free. Free.' is duplicated text that reads as a formatting defect and wastes the closing position. Net still compact, but sloppy.

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 no output schema, the description usefully enumerates the returned fields (subject, time, place, organizer, attendees, Meet link), and adds the 62-day limit needed to call it correctly. Given annotations cover safety, the remaining gaps (pagination, result ordering, behavior with multiple mailboxes) are moderate rather than disqualifying.

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% (start/end have no schema descriptions), and the description compensates by defining them as a bounded date range capped at 62 days and interpreted in UTC. That is exactly the missing semantics. The repeated 'Free. Free.' adds no parameter value, and mailbox behavior when multiple are connected is left to the 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?

The description names the resource (events in a mailbox's calendar) and the exact scope (between start and end, UTC) plus the fields returned. It is clearly a read/list operation and easily distinguished from google_calendar_create or google_calendar_cancel, though the verb is implied rather than stated and the sibling m365_calendar_events is never mentioned as the Microsoft counterpart.

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 explicit when-to-use guidance, no prerequisites (e.g. Google account must be connected via google_connect), and no routing to alternatives such as m365_calendar_events for Microsoft mailboxes, calendar_find_times, or calendar_list_bookings. The only guidance is implicit in the resource name.

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