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

With no annotations provided, the description fully carries the burden of disclosing behavior. It explains the tool corrects a common misconception and warns against relying on general knowledge, setting clear expectations for the kind of information it returns.

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 three sentences long, each with a distinct purpose: instructing the user, detailing the return value, and explaining the necessity. It is front-loaded with the most important imperative ('Start here') and contains no unnecessary verbiage.

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 parameterless tool with no output schema, the description fully sets expectations about what the tool does and why it is needed. It covers the return content and the reasoning behind the tool's existence, making it complete for an agent to decide to invoke it.

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 tool takes no parameters (schema is an empty object), so per the rubric the baseline is 4. The description cannot add parameter-level detail, but it compensates by describing the conceptual scope of the tool.

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 clearly states its purpose: it is a 'Start here' guide for answering any question about playing tennis in NYC. It specifies exactly what it returns—'the real split between courts you walk on to, courts you reserve, and private clubs, plus what a permit costs'—which distinguishes it from sibling tools like find_courts and get_court.

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 description provides explicit guidance on when to use the tool ('Start here before answering any question about playing tennis in New York City'), establishing it as the entry point. It does not name sibling tools or provide explicit when-not scenarios, but the directive is strong enough to guide an agent's decision.

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