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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered structurally. The description adds real business context beyond that: the stay is prepaid, non-cancellable and non-modifiable, and the key must come from the confirmation.

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 short sentences, front-loaded with the action and return fields, then the required key, then the business caveat. No filler, though the final reminder sentence is tangential to the retrieval action.

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?

With no output schema, the description usefully names the returned fields (dates, booking number, assigned room). Combined with the annotations covering read-only/idempotent semantics, an agent has enough to call this correctly; only the sibling routing remains unaddressed.

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?

There is a single parameter with 100% schema description coverage, so the schema already documents stay_key as 'La clé remise dans la confirmation.' The description repeats that same provenance without adding format, length, or validation detail, so the baseline of 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?

The description gives a specific verb+resource ('Relit un séjour déjà réservé') and enumerates what is returned: dates, booking number, assigned room. It is clear enough to distinguish from read siblings like get_folio or get_check_in, though it never names them or explicitly contrasts its scope.

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 states the precondition (the stay_key handed over in the confirmation) and hints at the mutation boundary by noting an agent-booked stay is prepaid and neither cancellable nor modifiable. However, it never says when to prefer this over get_booking_session or get_check_in, so usage is only implied.

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