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

Annotations already declare readOnly, idempotent, non-destructive behavior, so safety is covered. The description adds a genuinely useful trait beyond that: slot times are returned in the VENUE's timezone, which is not necessarily the directory's — a non-obvious behavior an agent would likely get wrong.

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 short sentences, front-loaded with the purpose, then prerequisites, then the timezone caveat. No filler sentences and nothing redundant with structured fields.

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 carries return-value burden and does address the key return detail (slot times plus their timezone). It does not describe the shape of the slot list or behavior when no slots exist, which is a minor gap for an otherwise complete definition.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: it names the source of serviceId (list_booking_services) and explains that place_slug must match the earlier call because it governs the returned timezone. That links a parameter to an observable output behavior rather than just restating 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 — 'Get available time slots for a bookable service on a given date' — and scopes it to Wix Bookings. This clearly separates it from list_booking_services, get_event_tickets, and the booking-creation siblings.

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?

Explicitly routes the agent to call list_booking_services first and reuse its serviceId and place_slug, which conveys the intended call sequence. It stops short of stating exclusions (e.g. what to do for multi-day ranges or unavailable dates), so it's clear but not fully exhaustive.

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