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

With no annotations, description carries full burden. It reveals the timezone nuance (venue's timezone not directory's) but fails to mention other behaviors like empty responses, error conditions, or scope (e.g., maximum date range).

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, no filler. Front-loaded with key action and domain. Every sentence adds distinct value (purpose, source of IDs, timezone caveat).

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?

No output schema, so description should hint at return format. It says 'slot times' but doesn't specify structure (array? time objects?). With moderate complexity (3 params, no nested objects), the lack of output detail leaves a moderate gap.

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 covers all parameters (100%), but description adds cross-reference to sibling tool (serviceId from list_booking_services) and critical timezone context for place_slug. This extra meaning justifies above-baseline score.

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 clearly states it retrieves available time slots for a bookable service on a given date. The verb-resource combo is specific, but it doesn't explicitly differentiate from sibling tools like 'get_showtimes' or 'request_reservation', though the domain (Wix Bookings) provides some context.

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 explicit context: pass serviceId from list_booking_services, same place_slug, date format, and crucial timezone note. No redundant alternatives, but the guidance is direct and actionable.

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