tier_checkout

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

No annotations are provided, so the description carries the full burden. It mentions returning a Stripe checkout URL and implies a subscription action, but lacks details on side effects (e.g., immediate charge, cancellation policy) or error behavior. Basic transparency is present but incomplete.

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?

The description is extremely concise, containing two sentences that cover purpose, alternative, identifiers, and return type without any fluff. It is front-loaded with the core action.

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?

Given the tool's simplicity (3 params, no output schema), the description covers purpose, alternative, identifiers, and output type. It could mention failure scenarios or URL expiration, but overall it is sufficiently complete for an agent to use 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?

The input schema provides full coverage (3 parameters). The description adds value by explaining the tier enum with cost/duration details and clarifying that email and wallet are for different account types, which aids proper usage.

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 clearly states the tool's purpose: subscribing/renewing/upgrading to a run402 tier via Stripe credit card. It distinguishes itself as an alternative to x402 on-chain payment, which differentiates it from siblings like 'set_tier'. The verb and resource are specific.

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?

The description provides when to use (credit card payment) and identifies alternatives (x402 on-chain). It also explains the supported identifiers (wallet or email). However, it does not explicitly state when not to use the tool or list other alternatives, which would be beneficial.

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