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

Annotations already declare it is a non-read-only, non-idempotent, open-world call, and the description adds substantial context beyond that: it creates a Stripe checkout, returns a payment link the user must open, and the Boost only activates after payment succeeds. It does not cover failure/cancellation behavior or whether repeated calls spawn multiple checkouts (relevant given idempotentHint=false).

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?

Purpose is front-loaded in the first clause, followed by pricing and payment flow. The dense price block is information the agent genuinely needs to quote to a user, so it earns its space; no filler sentences.

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 the return value (a payment link) and the deferred side effect (Boost starts after payment). Missing pieces are edge cases: link expiration, behavior on duplicate boosts, and whether a code can be boosted while already boosted.

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 50% and the undocumented parameter is `duration`; the description compensates by mapping the durations to human-readable windows (48h / 1 week / 3 weeks) and explaining that price varies by brand category. It could go further by enumerating the category tiers that correspond to each price band relative to a specific code, but the added meaning is real.

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 and effect: 'Create a Stripe checkout to pin one of the user's codes to the top of its brand page.' The scope ('one of the user's codes') and outcome (pinned placement) distinguish it from sibling tools like publish_code or list_my_codes without ambiguity.

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?

Usage is only implied: the agent can infer this is the paid-promotion path for a code the user owns, and the schema note 'Code id from list_my_codes' hints at the prerequisite call. There is no explicit when-to-use/when-not statement, no mention of alternatives such as subscribe_premium, and no guidance on what to do if the user declines payment.

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