calendar_get_free_busy

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

Annotations already cover the safety profile (readOnly/idempotent/non-destructive), and the description adds genuine behavioral context beyond that: the access-dependent fallback between full event details and free/busy slots, plus an 'auto-approved' note relevant to the approval workflow. It does not describe result shape or rate limits, but the added fallback semantics are substantive.

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?

Three tightly written sentences, front-loaded with the core purpose before the fallback nuance and usage note. Every sentence carries information, though the fallback clause is dense. No padding or repetition of the schema.

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 read-only query tool with full annotation coverage, full schema coverage and no output schema, the description supplies the access-dependent return behavior an agent would otherwise have to guess, which is the main gap it needed to close. Only minor omissions (result shape specifics, pagination) remain.

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 four parameters (emails, time_min, time_max, reason) are already documented in the schema. The description references emails and a time range generically but adds no format or interpretation detail beyond the schema. 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 ('Query colleagues' schedules for a time range') and scopes it to colleagues rather than the user's own calendar, which is the key distinction from siblings like calendar_list_events and calendar_get_event_details. An agent can identify what it does without opening the 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?

Provides the intended context ('Use this for meeting scheduling') but gives no when-not guidance and never names an alternative tool for related lookups (e.g., calendar_get_event_details, calendar_get_event_visibility). Usage is implied rather than contrasted.

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