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

Annotations only declare readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=false; the description adds real behavioral context the annotations cannot convey. It discloses that links open a one-month trial that then converts to paid, that no API key is required, that a quantity under 5 is refused, and the post-call workflow (collect the key from the success page and send it as an Authorization Bearer header).

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 core return value is front-loaded and most sentences carry operational weight (plan options, refusal threshold, OAuth alternative, how to use the link). There is mild sprawl in the final two sentences and the OAuth aside is slightly tangential for a tool whose job is returning links.

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 carries the burden of explaining what comes back, and it does so (Stripe Checkout links per plan). It also covers auth expectations on both paths, so an agent knows nothing needs to be passed and what to do with the returned link. Only edge details, such as whether quantity is meaningful when plan=individual, are left implicit.

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 schema already states 'Omit to open both' for plan and 'Below 5 is refused' for quantity, so the description largely repeats what the schema provides. It adds only the minor mapping that 'seat' means five or more people, which does not materially extend meaning beyond the structured fields.

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?

Opens with a concrete verb and resource: 'Returns Stripe Checkout links for Individual and Team,' which is unambiguous and matches the get_access title. It does not reference any sibling tool, though none of the listed siblings (account, my_contacts, etc.) overlap with billing, so the risk of mis-selection is low.

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 states the selection condition explicitly: 'These links are the display-key path for clients that do not use OAuth,' and contrasts that with the OAuth Subscribe path that needs nothing pasted. It also states the plan/omit semantics and the quantity-below-5 refusal. What is missing is only an explicit 'use this instead of X' phrasing against a named sibling.

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