list_events

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

Annotations already declare readOnlyHint=true and idempotentHint=true, and the description reinforces with 'Changes nothing.' It adds valuable behavior beyond annotations: recurring events are expanded to occurrences, and all-day events carry startDay/endDay with a clear definition of endDay. No contradiction with 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 concise sentences, with the core purpose front-loaded. Every sentence adds information: the scope, the recurring/all-day behavior, and the sibling pointer. Zero waste.

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?

The tool has 5 parameters (2 required) and no output schema, but the description covers key behavioral expectations (recurring expansion, all-day fields) and offers a relevant alternative. It doesn't mention pagination or output structure, but these are partially handled by maxResults in the schema, so the coverage is adequate.

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 all parameters (start, end, query, maxResults, calendarIds) are already fully documented. The description adds no parameter-specific semantics beyond what the schema provides, so the baseline 3 is appropriate.

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 opens with a specific verb-resource pairing ('Reads events in a date range') that clearly distinguishes it from mutating siblings like create_event/update_event/delete_event. It further contrasts with find_free_time by naming it explicitly, so an agent knows exactly what this tool does and what it doesn't.

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 gives an explicit alternative ('For free gaps rather than busy events, use find_free_time') and states the behavior for recurring and all-day events. It lacks an explicit 'when not to use' for other siblings, but the read-only nature and the free-time pointer cover the main usage decision.

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