Find Free Time

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safe-read profile is covered. The description adds genuinely useful behavioral context beyond that: it only sees the caller's own calendar in personal accounts, and slot suggestions are constrained to working hours. It does not mention the 62-day range cap or return shape, but the output schema covers results.

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?

A single well-formed sentence with the core action (show busy time, suggest free slots) front-loaded, followed by the scoping caveat. No waste, though it is dense enough that it could be split for readability.

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?

With rich annotations, a full output schema, and 100% schema coverage, the description only needs to add what structured fields cannot: the personal-account visibility limit and the working-hours assumption. It does that, so an agent has enough to call it correctly, though the range cap is left to the schema.

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 eight parameters are already documented in the schema, establishing the baseline of 3. The description adds only limited extra meaning, mainly re-explaining slot_minutes and the working-hours constraint, which the schema already conveys.

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 states a specific verb and resource: it shows busy time in your own calendar and suggests free slots of a given length. The scope note ("this covers your calendar only") clarifies what it queries, though it never names a sibling tool like calendar_create_event to route against.

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?

Usage is implied rather than stated: an agent can infer it should call this before scheduling a meeting, and the personal-account limitation tells it not to expect others' availability. There is no explicit when-to-use/when-not guidance or named alternative tool.

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