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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds the useful behavioural detail of what content comes back (brand, setting, treatment rooms, couples suites, signature treatments), which partially compensates for the absent output schema, but says nothing about scoping, empty results, or ordering.

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?

It is a single short fragment with no wasted words, but it is a noun-phrase list rather than a front-loaded statement of action. Conciseness is achieved at the cost of under-specification.

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 field enumeration is genuinely useful in conveying what is returned. However, the description omits the one thing an agent must know to invoke it correctly: that the response is spa venues for the property identified by slug.

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 ('Canonical property slug'), so the schema already carries the semantics and the baseline is 3. The description adds no clarification of the slug or its relationship to sibling tools such as resolve_resort.

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 names the resource ('Spa and wellness facilities') and enumerates the data it covers, but never states a verb or the fact that results are scoped to a single property via the required slug. An agent can infer this is a spa listing tool, but the phrasing reads like a field catalogue rather than a statement of what the tool does.

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?

There is no when-to-use guidance and no mention of the close siblings that serve parallel content (list_dining, list_villas, list_experiences). Nothing tells the agent that a property slug is a prerequisite, or how this differs from other per-resort listing tools.

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