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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: service windows (6am-9pm), the surcharge consequence of out-of-hours pre-booking, and the constraint that travel within 12 hours cannot be handled here. It does not describe the shape of the answer, which is a minor gap.

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 tight sentences with no filler, front-loading the core purpose before the hours and fee caveats. The density of rules in the second and third sentences is high but each clause carries operational meaning.

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 read-only availability check with no output schema, the description covers purpose, service hours, pricing side-effects, and an escalation rule. The main omission is what a positive or negative result looks like, but with a simple boolean-style check that is a small 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 description coverage is 100%, so date, time, and pax are already fully documented with formats and the 1-14 passenger range. The description adds no parameter-level detail, which is acceptable given the schema does the work, but it earns only the baseline.

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 states a specific check (can CGC service a pickup) on clear resources (date and time), so the agent knows this is a feasibility lookup rather than a booking or pricing call. It is distinguishable from request_booking and get_quote, though it never names those siblings directly.

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?

It supplies useful operating conditions — standard hours, out-of-hours fees, and a 12-hour lead-time rule requiring direct contact — which imply when this tool is appropriate. However, it never explicitly routes the agent to alternatives (e.g. get_quote for the fee amount), so selection guidance is only implied.

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