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

Goes well beyond the annotations by disclosing traits annotations cannot express: the link signs the user into checkout, it is single-use ('works once'), and it expires after 10 minutes. These are exactly the constraints an agent must respect to avoid handing the user a dead link, and they are consistent with the non-idempotent, non-read-only annotations.

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?

Four sentences, zero filler: purpose first, then the sign-in/credit mechanics, then the single-use/expiry constraint paired with the usage condition, then the parameter caveat. Every sentence carries decision-relevant 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?

With an output schema present, return format need not be described, and safety/permission behavior is covered by annotations plus the expiry and single-use disclosure. Nothing an agent needs in order to call this correctly 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; the description adds real meaning by stating that Buying Club credit is applied by default and naming the exact opt-out condition ('set use_wallet to false if the user doesn't want to use their credit'). That is more than a restatement of the schema's default note.

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 resource ('Get a secure checkout link for the signed-in user's cart') and is instantly separable from sibling cart tools like suppco_get_my_cart and suppco_add_to_cart, since a checkout URL is a distinct artifact. The added clause about sign-in for member pricing clarifies the resource's nature rather than restating the name.

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 when-to-use condition ('call this only when the user is ready to pay and give them the link right away') plus a default-behavior caveat for use_wallet. It does not name a sibling alternative or a precondition such as needing items in the cart, so it falls just short of the 5 bar.

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