Query calendar free/busy

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

With no annotations, the description carries the full behavioral burden, and it does disclose one genuinely valuable failure mode: an unreadable calendar surfaces errors rather than appearing free, which prevents false 'available' conclusions. It leaves out whether the call is strictly read-only, permission/auth expectations, and what the response shape looks like.

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 sentences, zero filler, with the core purpose front-loaded and the caveat about partial failures placed immediately after. Every clause carries information.

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 5-parameter read tool with full schema coverage and no output schema, the description covers purpose and the key error behavior. It could go slightly further in describing the returned busy-interval structure or timezone/range edge cases, but nothing critical for correct invocation is missing.

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 five parameters (items, account, timeMin, timeMax, timeZone) are already documented in the schema. The description adds no parameter-level meaning beyond that, which is the expected baseline when the schema does the work.

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 ('Query busy intervals across calendars') and adds the practical intent ('find free meeting windows'), which distinguishes it from google_calendar_list_events at a conceptual level. It never names that sibling explicitly, so differentiation relies on the agent inferring the busy-vs-detailed-events distinction.

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 phrase 'to find free meeting windows' implies the usage context, but there is no explicit when-to-use/when-not guidance and no mention of alternatives such as google_calendar_list_events for event details. Usage must be inferred from the purpose sentence.

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