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

With no annotations, the description must carry the behavioral burden. It usefully conveys that the tool returns a Stripe URL and that the human pays later, implying no direct charge. However, it does not disclose whether invoking this creates or mutates a Stripe checkout session, whether the link expires, or how invalid IDs are handled.

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?

Two short sentences with no filler. The main return value is front-loaded, and the purpose is stated in the second sentence, making it easy to parse.

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 one-parameter, no-output-schema tool, the description is nearly complete: it names the return value (URL) and the intended next action. It falls slightly short by not addressing possible side effects or validity requirements, though those are not critical for this simple use case.

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% and the schema already explains that id is an offer id or slug. The description adds only the word 'product', which roughly maps to offer, so no meaningful parameter information is added beyond the schema.

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 uses a specific verb ('Return') and names a concrete resource ('the live Stripe payment link for a product'), immediately distinguishing this from offer-listing or offer-detail tools in the sibling set. The second sentence clarifies the intended human-facing purpose.

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 clear context: use when you need a payment URL to hand to a human to pay. It does not explicitly name alternatives such as get_offer or list_offers, nor state when not to use it, so it stops short of a 5.

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