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

Annotations already indicate idempotency, and the description adds concrete meaning by explaining that adding a lounge already on the wishlist is a no-op. This clarifies the actual runtime behavior beyond what the annotation alone communicates.

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?

The description is two short sentences with no filler. It front-loads the primary action and includes only the essential behavioral note about idempotency.

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 single-parameter mutation with no output schema, the description and annotations provide enough context for correct invocation. It could mention response or error behavior, but nothing critical is missing for a typical use case.

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?

The schema already fully documents lounge_slug as 'Lounge slug (from search results).' The description adds no additional parameter-level detail, so the baseline for high schema coverage 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 states a specific action and resource: 'Add a lounge to your wishlist.' It clearly distinguishes the tool from read-only siblings like get_my_wishlist and from remove_from_wishlist, though it does not explicitly name them.

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 intended use is obvious from the description, but it does not provide explicit guidance about when to use this tool versus alternatives such as remove_from_wishlist or mark_lounge_visited. Usage is implied rather than directly contrasted.

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