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

With no annotations, the description carries the full load. It usefully discloses the authentication requirement (valid Druk Asia API key sent automatically via the x-api-key header) and implies a read-only check, but it says nothing about what the returned status looks like (pending vs failed vs succeeded), whether the check is cached or rate-limited, or what happens for an unknown booking id.

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 short sentences, with the core purpose front-loaded and the auth note trailing. The auth sentence is somewhat boilerplate for this API family since the key is sent automatically, but it is not misleading and costs little.

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 tool is low complexity with one fully documented parameter, but it has no output schema and no annotations, so the description should have characterized the possible status results. As written, an agent knows how to call it but not what to expect back.

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% for the single parameter, and the schema itself explains that online_booking_id is OnlineBookings.Id from create_booking. The description adds no further meaning about the identifier, so the baseline 3 is appropriate when the schema does the work.

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 uses a specific verb and resource: it checks whether a booking's payment has succeeded, which distinguishes it from create_payment (initiates) and get_booking (returns booking data). It stops short of naming a sibling to contrast with, so it is clear but not explicitly differentiated.

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?

Usage is only implied: an agent can infer this is the follow-up call after create_payment or with a booking_id from create_booking. There is no explicit statement of when to use it versus get_booking, nor any when-not guidance or prerequisite ordering.

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