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

readOnlyHint=true already establishes the safety profile, so the description's job is to add context beyond that — and it does, enumerating the concrete fields returned (prepayment/deposit status, channel reference id, guest-app URL) in the absence of an output schema. It stops short of noting auth scope or error behavior for a missing/invalid 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?

One sentence, front-loaded with the action and lookup key, followed by the returned payload and the underlying API route. No filler; every clause carries information.

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 single-entity read with no output schema and one fully documented parameter, the description is nearly self-sufficient — it tells the agent what the call returns. Only the absence of any failure-mode or id-provenance guidance keeps it from being fully complete.

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% and the single parameter carries its own description ('The reservation (booking) id.'), so the schema does the heavy lifting. The description's 'by id' reinforces the lookup key but adds no format, type, or constraint detail beyond the schema. Baseline 3 applies.

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?

States a specific verb (Fetch) and resource (one reservation) scoped by id, and enumerates the returned payload (guest, dates, check-in/out times, channel, price, prepayment/deposit status, guest-app URL). The word 'one' plus 'by id' cleanly separates it from smoobu_list_reservations without needing the sibling's schema.

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 'by id' phrasing implies the caller must already hold a reservation id, which is useful context, but the description never states when to prefer this over smoobu_list_reservations or smoobu_get_reservation_placeholders, nor any prerequisites. Usage is inferable rather than explicit.

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