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

Annotations already establish read-only, idempotent, non-destructive and closed-world behavior, so the bar is low. The description still adds real value by warning that the result is static directory metadata rather than live availability, preventing an agent from treating it as a freshness source; it says nothing about behavior for an unknown or malformed ID.

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 sentences, no filler: the trigger condition and returned fields come first, and the scope caveat follows. Every clause earns its place.

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 an output schema present, the description needn't explain return values, and the prerequisite plus the live-vs-static distinction cover the call decision. The only material gap is how to obtain a valid club_id, which the sibling search_clubs would supply.

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 0% for the single club_id parameter, so the description must compensate. It signals that the value is a pre-existing "Zarvo club ID" rather than a free-text name, which is useful, but it never mentions the kebab-case slug format encoded in the schema pattern or where such an ID originates.

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 (a Zarvo padel club) and enumerates exactly what is returned — address, coordinates, facilities, racket rental, contact, website, socials — so the agent knows the payload without opening the output schema. It does not name the sibling that finds the ID (search_clubs), leaving the differentiation only partially explicit.

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?

"Use this after a Zarvo club ID is known" is an explicit prerequisite, and "returns directory metadata, not live availability" excludes the availability siblings. It stops short of naming search_clubs as the way to obtain the ID or get_availability as the alternative for live data.

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