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

Annotations only say readOnlyHint=true and openWorldHint=true; the description goes further by clarifying that nothing is charged, that a human must open the URL and complete payment, and that the link is tied to the caller's token. That resolves the real ambiguity behind 'read-only' for a payment-adjacent tool, though it omits link expiry or failure behavior.

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?

Three short sentences with zero padding, front-loading the usage restriction before the return value and the payment caveat. Every sentence carries distinct information.

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?

There is no output schema, so the description must characterize the return value — and it does, naming the Stripe Checkout URL and the billing consequence. For a two-parameter, single-purpose tool, an agent has everything needed to call it correctly.

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 100%, so the baseline is 3, but the description adds information the schema lacks: the concrete prices for each enum value ($3/mo Hobby, $15/mo Pro) and the token's origin (deed_tok_ from first publish). The token's optionality is covered by the schema rather than the description.

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?

States a specific verb+resource (returns a Stripe Checkout URL) and names both plan tiers with prices. Nothing about it overlaps with the site-management siblings, so an agent can immediately tell this is the monetization/upgrade 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?

Gives an explicit gating condition — 'Use this only when the user asks for higher limits' — which is a clear when-to-use with a restriction. It does not name an alternative path to upgrading, but no sibling tool offers one, so the gap is minor.

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