list_calendar_events

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuine behavioral context beyond that: the failure mode ('one date alone throws') and the fact that the same events surface in getScheduledWorkouts' feed as itemType 'event'.

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?

It is a single compact sentence, but it is front-loaded with a cross-reference ('Events also appear in...') rather than the primary action, and the semicolon chain makes it dense. The most important content (what the tool does) sits after the endpoint trivia.

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?

For a simple two-optional-param list tool with annotations covering safety, the call semantics (date combinations, error case) are adequately covered. With no output schema present, however, the description gives no sense of what an event record contains or whether results are paginated.

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 100%, so baseline is 3, but the description adds real semantics the schema lacks: the two dates must be supplied together (or not at all) and the range is inclusive. This is meaningful constraint information beyond the per-field format descriptions.

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 never states a clean verb+resource phrase like 'lists calendar events'; instead it opens with a cross-reference and an endpoint path ('this GETs /calendar-service/events'). The resource is inferable from the name and endpoint, and it does differentiate from getScheduledWorkouts' month feed, but the core purpose statement is vague and back-loaded.

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?

It clearly states the usable parameter combinations: both dates for an inclusive range, no params for the whole account, and explicitly warns that one date alone throws. It also points to getScheduledWorkouts as an overlapping source, giving the agent routing context, though it doesn't frame a full when-to-use-this-vs-that rule.

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