calendar_freebusy

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

With no annotations, the description carries the full burden. It discloses the key behavior of returning busy time blocks and uses 'Query' to imply a read-only operation. However, it lacks additional context such as timezone handling, default calendar selection, or whether free blocks are also returned, leaving significant behavioral details unspecified.

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 very short and front-loaded with the main action. However, the second sentence ('Returns busy time blocks') partially restates the first, and the description could add useful details without becoming verbose. It is appropriately concise but slightly redundant.

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 4 parameters and an output schema, but the description provides minimal guidance on invocation. It lacks parameter syntax, how calendars are chosen when null, and details about return format. An agent would need to infer too much from the schema alone, making the description incomplete.

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 0%, so the description needed to compensate. It does not explain time_min/time_max format, timezone defaults, or the semantics of the calendars array. Param names provide minimal insight, but timezone and calendars require elaboration that is absent.

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 operation ('Query') and the resource ('free/busy info for calendars'), and notes it returns busy time blocks. This distinguishes it from sibling calendar tools like calendar_get_events or calendar_create_event, making the purpose unambiguous.

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 use for checking calendar availability, but it does not explicitly specify when to prefer this over calendar_get_events or calendar_list_recurring_instances. No alternatives or exclusions are mentioned, so guidance is only implicit.

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