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

Annotations only declare destructiveHint=true; the description adds meaningful behavior beyond that — partial-update semantics, immutability of the listing field, no cancel/reprice side effects, and the channel-overwrite caveat on dates. It omits permission/auth requirements and what the response returns, which keeps it from 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 verb and scope, followed by the partial-update rule and then the constraints. Every clause carries information; 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 25-parameter mutation with no output schema and only a destructiveHint annotation, the description covers scope, partial-update mechanics, hard exclusions and a channel-specific risk. Auth/permission requirements and the shape of the result are unstated, but the essential operational picture is present.

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% so the baseline is 3, but the description adds real semantics beyond the schema: the instruction that only changed fields should be sent (all 24 optional params are partial-update inputs) and that listing must not be provided. It does not clarify formats like the arrivalDate/departureDate pairing or door-code vendor interaction.

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 (change fields on an existing reservation) plus the resource and the field categories affected (guest details, dates, door code, notes). It also names what it is not relative to siblings: not a create, not a cancel, not a reprice.

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 concrete operating context: 'Send only the fields to change' (partial update), listing is immutable via this tool, and date changes on channel bookings may be overwritten. It does not explicitly say when to prefer this over siblings like hostaway_update_calendar or hostaway_create_reservation, so it falls short of a 5.

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