calendar_free_busy

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

The description adds behavioral details beyond the readOnly/openWorld annotations: missing or failed sources are treated as unknown/free, and concurrency limits are specified. It does not describe output format, but the behavior for failures is valuable.

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 concise, with no unnecessary words. It front-loads the core purpose and then adds key constraints and behavioral notes.

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 description provides sufficient context for an agent to understand the tool's scope, limits, and edge case behavior. It does not include output format, but in the absence of an output schema, the purpose and failure semantics are enough for basic use.

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?

The schema covers 3 parameters, but none have descriptions. The description clarifies that 'calendars' are explicit account/calendar pairs, and mentions a maximum window of 31 days, but does not explicitly define timeMin/timeMax as the window boundaries. This leaves some ambiguity.

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 action (read free/busy) and the resource (explicit account/calendar pairs), and includes additional operational details like batching and concurrency limits. It is distinct from sibling tools like calendar_find_availability by focusing on explicit pairs.

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 provides some usage constraints (max 50 calendars per request, 4 concurrent requests, 31-day max window) but does not explicitly compare to alternative tools or state when to prefer this over others. It gives implicit guidance through the 'explicit pairs' phrasing.

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