calendar_upcoming

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

No annotations exist, so the description carries the burden. It does disclose behavior beyond the schema: events are aggregated across ALL calendars and ordered as the 'next' upcoming ones. However it says nothing about permissions, timezone handling, whether recurring/all-day events are included, or pagination, which are meaningful gaps for an unannotated tool.

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?

Two tight sentences with zero filler, and the core scoping fact ('across all calendars') is front-loaded before the sibling comparison. Every clause earns its place.

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 one-parameter, read-only list tool with no output schema, the description covers what it returns and how it differs from alternatives. It omits ordering/timezone specifics, but the schema carries the only parameter and no return structure needs explaining.

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%: the single 'limit' parameter already documents itself with its default of 10. The description only echoes this as 'N' without adding format or constraint detail, 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?

States a specific verb and resource ('Get next N upcoming events') plus a clear scope ('across all calendars'), and explicitly differentiates from a sibling by calling itself 'simpler than calendar_search'. An agent can distinguish this from search and the other calendar tools 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 alternative (calendar_search) and gives a condition for preferring this tool ('quick schedule overview'). It stops short of stating explicit exclusions or prerequisites, so it is clear context without full when-not guidance.

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