List events

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds real behavioral value the annotations lack: recurring events appear once per date, month view semantics, and timezone handling. Only minor ambiguity is that 'start and end are UTC' appears to describe returned fields rather than the schema's two params, which is not a contradiction but slightly unclear.

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?

Front-loaded with scope and output summary, then the sibling routing. Two tight sentences plus an informative clause; the 'title, time, place and who can join' list earns its place by previewing the return shape absent an output schema.

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 summarizes the returned fields and discloses recurring-event deduplication and timezone semantics. Nothing essential is missing for a simple two-param read tool, though pagination/limits and the exact meaning of the UTC note could be tighter.

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% — both 'group' and 'month' are documented with format and default — so the schema carries the parameter burden. The description reinforces month scoping ('in one month') but adds no format or syntax detail beyond the schema, matching the baseline 3.

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 ('Events on a group's calendar') plus scope ('in one month') and even previews the returned fields. It explicitly distinguishes itself from get_event and create_event, so an agent can pick it without opening a schema.

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?

Names the two relevant alternatives and what each does ('get_event returns one event, create_event adds one'), which effectively routes the agent. It doesn't spell out exclusions (e.g., multi-month ranges, non-calendar event sources), so it stops short of a full when/when-not rubric.

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