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

With no annotations, the description carries full burden. It discloses a key behavioral trait: slot times are returned in the venue's timezone, which may differ from the directory's. This is valuable context for correct interpretation of 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?

The description is concise, using two sentences to convey all essential information without unnecessary words. It front-loads the core purpose and then details parameter usage and behavioral context efficiently.

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?

Given the tool's simplicity (3 params, no output schema), the description covers what the tool does, how to use parameters, and a critical behavioral note (timezone). It is adequate for correct invocation, though some may desire information about return format.

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% with parameter descriptions, but the description adds meaning: it explains the relationship between serviceId and list_booking_services, reinforces the date format, and emphasizes that place_slug should be consistent. This adds value 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?

The description clearly states the tool's purpose: 'Get available time slots for a bookable service on a given date.' It specifies the action ('Get'), resource ('available time slots'), and context ('Wix Bookings'), effectively distinguishing it from sibling tools like create_booking.

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?

The description provides explicit usage guidance: pass serviceId from list_booking_services, date in YYYY-MM-DD, and the same place_slug. It also warns about timezone differences. While it doesn't explicitly state when not to use, the guidance is clear and actionable.

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