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

With no annotations, the description carries the full burden and excels: it discloses automatic renewal, credit accrual to the next reservation, Stripe Checkout flow, and failure if already a member. This is exemplary behavioral disclosure beyond the schema.

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 compact and information-dense, front-loading the core action followed by relevant caveats. Every sentence contributes valuable context, and the structure (em dashes, separate clauses) aids readability without unnecessary fluff.

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 subscription tool with financial implications, the description covers action, pricing, renewal, credit rules, payment URL, security note, and failure condition. However, the token parameter is unexplained, which is a significant gap in completeness.

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 has a single required `token` parameter with no description, and the tool description never explains what token represents or how to obtain it. With 0% schema coverage, the description fails to add any meaning to the parameter, leaving the agent without guidance.

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 it starts the annual Cancun4me Club subscription, specifies the cost (USD 1,000/year) and key terms. It distinguishes itself from sibling tools by mentioning get_membership_status as a prerequisite check, making the purpose unambiguous.

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?

It explicitly tells the agent to check membership status first with get_membership_status and warns never to collect payment data, instead directing to Stripe Checkout. This provides clear when-to-use and when-not-to-use guidance, including a failure condition if already a member.

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