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

Annotations already cover the mutation/open-world/idempotency profile, but the description adds real context beyond them: no key is required, the quantity floor of 5 is enforced server-side, and the returned key is shown only once. It does not cover rate limits or what a repeat call yields, which keeps it short of a 5.

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?

It is front-loaded with the return value and then walks through params, validation, and auth. The quantity floor is stated twice (description and schema), a small redundancy, and the sentences are choppy, but every sentence carries information and nothing is padding.

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 correctly explains what is returned (Checkout links, and a key shown once on the payment page) and covers auth requirements and parameter behavior. For a 2-param, no-required-params tool this is close to complete, though it omits error/retry behavior and any idempotency implications of re-requesting links.

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 coverage is already 100%, so the baseline is 3, but the description adds genuine meaning: it defines what 'seat' means ('a team of five or more'), clarifies omitting plan returns both links, and restates the quantity refusal rule. This enriches the enum semantics beyond the schema's terse 'Which checkout to open.'

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 verb+resource ('Returns Stripe Checkout links for Individual and Seat') and defines both plan types. It is clear on its own, but the name/title ('get_access' / 'Get a key') frames it as key retrieval while the body describes checkout-link generation, and it never contrasts itself with any sibling tool.

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 routes the agent: 'These links are the display-key path for clients that do not use OAuth' names the alternative (OAuth Subscribe) and the condition that selects this tool. It also states the post-payment flow ('open one, pay, and the page shows an API key once'), so when and when-not to use it is fully specified.

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