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

Goes well beyond the annotations (which only say it is non-read-only, idempotent, non-destructive, open-world) by disclosing that no card is charged autonomously, that price/price-id/name/currency are resolved server-side and client values are ignored or rejected, that the session is short-lived, and exactly what is returned.

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?

Front-loads the side-effecting warning and keeps every sentence substantive, though the em-dash-laden clauses make it denser than it needs to be.

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 return-value burden and does so precisely (hosted checkout URL, product summary, exact price, expiry), plus server-side price resolution and product eligibility — nothing an agent needs to call it safely is missing.

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 real meaning by explaining that client-supplied price/amount/currency/name/price-id will be ignored or rejected and that quantity is hard-fixed to 1 — useful given additionalProperties is false.

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 precise verb+resource ('creates a short-lived Stripe Checkout session/link') and scopes it to ONE product with quantity fixed at 1, which clearly separates it from read-only siblings like get_product_details and search_products.

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?

Marks the tool as SIDE-EFFECTING and states rejection conditions (unaudited/deprecated/not agent-sellable products), which implies when it can be used, but never names an alternative or tells the agent when to prefer a sibling such as get_product_preview or get_purchase_access.

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