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

With no annotations provided, the description carries the full burden. It discloses requirements and the return confirmation, but it does not mention side effects such as payment charges, ride scheduling behavior, or cancellation consequences. It is not misleading, but it lacks depth for a mutation operation.

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 two concise sentences, front-loaded with the action and including requirements and return value. Every sentence serves a purpose with no redundant wording.

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?

For a tool with 10 parameters, the description covers the core booking action and return value but omits notable optional behaviors like scheduled rides (is_later, trip_start_time) and payment method options. The schema fills these gaps, but the description alone would not fully prepare an agent for all use cases.

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?

The input schema has 100% description coverage for parameters, so the baseline is 3. The description adds little beyond the schema: it repeats the vehicle_type source and mentions payment method generically, but does not clarify the meaning of payment_opt values or the scheduling parameters (is_later, trip_start_time).

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 a clear action and resource: 'Book a Rovv ride.' It distinguishes itself from siblings like cancel_ride and get_current_ride by explicitly indicating a booking action. The return value is also stated, further clarifying its purpose.

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 states a clear prerequisite: 'a vehicle_type ID (from get_fare_estimate),' which tells the agent to use this after fare estimation. It does not explicitly contrast with alternatives like cancel_ride, but the requirement provides useful usage context beyond mere action.

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