calendar_list_events

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description still adds real value beyond them: the 366-day maximum span, the requirement for explicit UTC offsets and an IANA timezone, and the 'permissions: calendar' authorization requirement, none of which appear in the annotations.

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 compact clauses with the range bound and timezone requirement front-loaded before the version/permission tag. The bracketed metadata is marginally useful but is the only element not directly helping an agent call the tool.

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 an output schema present, return values need no explanation, and annotations cover the safety profile, so the description is nearly sufficient. The remaining gaps are the undocumented 'limit' cap/behavior and whether calendarIds defaults to all calendars, which an agent would need to guess.

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?

At 60% schema coverage, the description reinforces the start/end/timezone formats already documented in the schema but adds the non-obvious 366-day span limit that the schema does not express. It says nothing about 'limit' (empty schema description) or what calendarIds defaults to, leaving part of the coverage gap unfilled.

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') plus a scoping qualifier ('intersecting a bounded time range'), which cleanly separates it from calendar_find_free_slots and calendar_list_calendars. It does not name any sibling explicitly, so it stops short of full differentiation.

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 choose this tool over calendar_find_free_slots or calendar_list_calendars, and no stated exclusions. Only hard constraints (366-day bound, timezone requirement) are given, which are validation rules rather than usage routing.

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