find_free_slots

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

Annotations already declare readOnly/idempotent/non-destructive, so the bar for extra disclosure is met with the connected-calendar prerequisite and the explicit statement that it never books. It also discloses that time zone, weekends, working hours, minimum notice and inter-event gaps are handled internally, which is genuine non-obvious behavior.

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?

Front-loads the return shape in the first sentence and packs routing, precondition and safety notes into a compact block. Slightly dense but every sentence carries a distinct fact; nothing is padding.

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 no output schema, the description compensates by describing the return structure ({count, slots:[{start,end,label}], nota}) and the meaning of `label`. Combined with the auth prerequisite and the booking-side routing, an agent has everything needed for a 7-param, all-optional tool.

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 the schema already documents all seven parameters, and the description adds no per-parameter syntax or format detail. Its mention that working hours, weekends, notice and gaps are 'already handled' loosely maps to work_start/work_end, skip_weekends and min_notice_hours but adds no new semantics beyond the schema.

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 — computing free meeting slots from the calendar — and explicitly names the sibling it replaces (list_events) and the sibling that books (create_event). An agent can select it without opening any 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?

Gives an explicit routing rule ('use this instead of deriving availability from list_events') plus the write-path alternative ('use create_event for that, which needs human approval'). It also states the precondition of a connected Microsoft or Google calendar.

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