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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description contributes one genuine scope disclosure beyond the annotations: 'Membership fees are not returned', which tells the agent the comparison is incomplete on cost. No return format, pagination or failure behavior is described, so the added value is real but thin.

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?

A single sentence with zero filler. The compared facets are front-loaded and the caveat about membership fees closes it out efficiently.

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 usefully enumerates the fields the comparison yields and flags what is excluded, which is enough for an agent to know whether to call it. It stops short of stating cardinality behavior (e.g. what happens if a slug is invalid) or response structure.

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% and the single parameter is already documented as '2-3 club slugs to compare'. The description's 'by slug' and 'two or three clubs' merely restate the schema, adding no syntax or format detail beyond it; baseline 3 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?

States a specific verb (compare) and resource (clubs) and enumerates the compared facets: location, waitlist status, course details, amenities, website. This clearly distinguishes it from the single-entity siblings like get_club, though it never names an alternative explicitly, so it stops short of a 5.

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 multi-club 'compare two or three' framing implies the use case (evaluating several clubs side by side) versus fetching one, but there is no explicit when-to-use or when-not-to-use statement, nor any reference to get_club or search_clubs. Usage is inferable rather than stated.

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