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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description goes beyond that by disclosing the concrete data surface returned (guest contact, price breakdown, payment state, door code, notes, channel, cancellation policy), which meaningfully helps an agent judge whether this call yields what it needs. It omits auth scope, rate limits, and error/not-found behavior.

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 tight sentences: the core action and the returned-data summary are front-loaded, and the trailing REST endpoint reference is compact. No filler or redundancy.

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's enumeration of returned fields is exactly the compensating detail an agent needs for a single-resource fetch. Given the trivial one-parameter schema and readOnly annotation, nothing essential 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?

There is a single parameter with 100% schema description coverage, so the schema already carries the semantics; baseline 3 applies. The description only restates 'by its Hostaway id' and adds no format or constraint detail beyond the schema.

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 and resource ('Fetch a single reservation by its Hostaway id') and enumerates the payload the caller will receive. This clearly distinguishes it from hostaway_list_reservations and hostaway_update_reservation without needing to open any 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 phrase 'by its Hostaway id' implies you need a known id (vs. listing), which is a mild routing signal. However, no alternative sibling is named and no when-not-to-use condition or prerequisite is stated, 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.