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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It clearly states that nothing is booked until payment, the booking stays off the calendar until a human pays, and the contact email is not verified. These are critical side effects and state changes that an agent must know.

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?

Every sentence in the description carries essential information: the action, the payment caveat, the instruction to tell the user, the prerequisite call, and the email verification limitation. It is front-loaded with the core purpose and wastes no words on redundant details.

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?

The description is complete for a tool with six parameters, a nested contact object, and no output schema. It explains the return value (checkout URL), the necessary precondition, and the consequence of not completing payment. The level of detail leaves no critical ambiguity for an agent invoking this 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 fully documents all parameters and nested fields. The description does not add parameter-level details beyond the schema, but it reinforces the necessity of using `get_availability` output for start/end dates. Per the rubric, high coverage yields a baseline of 3.

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 opens with 'Book an appointment slot at a venue (Wix Bookings)', giving a specific verb and resource. It then clarifies the tool's actual behavior—returning a checkout URL rather than finalizing the booking—which distinguishes it from the sibling `create_checkout` and prevents misuse.

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 explicitly instructs to 'Call get_availability immediately before this' and warns that a taken slot will be rejected. It also tells the agent to 'Tell the user they must open the link', providing clear when-to-use and follow-up guidance. This effectively differentiates the orchestration flow from alternatives.

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