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

Annotations only supply destructiveHint=true, so the description carries most of the burden and delivers meaningful behavior: partial-update semantics (unsent fields untouched), scope limits (no dates/property), and the underlying PUT endpoint. It omits permission requirements and error/response behavior, keeping it below a 5.

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, front-loaded with the action and the mutable field set, then the patch rule and the exclusion, ending with the API reference. No filler.

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 17-parameter mutation tool with no output schema and minimal annotations, the description covers mutability scope, patch semantics, and exclusions adequately. It could still say more about side effects or validation failures, but nothing essential for correct invocation is missing.

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 all 17 parameters including status enums and HH:mm patterns are already documented. The description's field grouping adds mild orientation but no syntax or format detail beyond the schema, matching the baseline 3.

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+resource ('Update an existing reservation') and enumerates the mutable field groups (times, guest contact, notes, counts, language, money/paid status), which cleanly separates it from smoobu_create_reservation and smoobu_get_reservation.

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?

Gives clear usage context: 'Only the fields you pass are sent' clarifies patch semantics, and 'Dates and property cannot be changed here' states an explicit exclusion. It stops short of naming an alternative tool for date/property changes, so it is not a full when/when-not routing prescription.

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