calendar_list

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It adds a useful behavioral detail: times are returned in UTC. It does not explicitly state that this is a read-only operation, nor does it describe pagination, response structure, or ordering, but the verb 'list' implies a non-destructive read.

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?

The description is two sentences long and every word earns its place: it states the action, the resource, the timeframe, and the timezone. There is no redundant or filler content.

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?

Given the low complexity (2 optional parameters, no nested objects) and full schema coverage, the description is reasonably complete. Without an output schema, it mentions the return type (calendar events) and the timezone (UTC). It could be more explicit about returning event details, but for a simple list tool, it provides adequate context.

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 the schema fully documents both parameters (account and days_ahead). The description adds no additional meaning about these parameters beyond the schema's own descriptions, so the baseline score of 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 clearly states the tool's purpose with a specific verb and resource: 'List upcoming calendar events'. It adds a timezone detail ('Times are returned in UTC') that helps specify the output. However, it does not distinguish this list tool from its sibling tools like calendar_search or calendar_get, which likely overlap in scope.

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?

The description implies usage when you need upcoming events, but it gives no explicit guidance on when to prefer this tool over alternatives such as calendar_search or calendar_get. There are no exclusions or alternative tool references, leaving the agent to infer the intended use case from the tool name and the word 'upcoming'.

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