topup_credits

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

No annotations are provided, so the description carries the disclosure burden. It explains the two method behaviors (async USDC feed, Stripe checkout for a human to complete) but doesn't say whether there are reversibility, confirmation, or latency implications. The disclosure is useful but incomplete for a mutation/payment tool.

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 sentences total, front-loaded with the core purpose, and every clause adds value. There is no fluff or repetition of schema fields. The alternative payment flows are packed concisely.

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?

Covers when to use and how to use the main payment paths, but no output schema or annotations to fill for the return value of the USDC path. The description doesn't state what is returned when reporting payment with tx_hash, nor an explicit guard that Stripe requires a human step. These gaps make a few details left to guess.

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?

Param schema covers all names and types (100% coverage), but the description adds meaning by linking 'tx_hash' to the USDC method and clarifying that Stripe returns a checkout link for a human. This provides conditional logic between method and tx_hash beyond the structured 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 opens with a specific action and resource: 'Add credits when your $5 free balance runs out.' It clearly distinguishes this from sibling tools like purchase_data or check_balance by framing it as a balance top-up operation. The verb and subject are unambiguous.

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?

Explicitly states when to use: 'when your $5 free balance runs out.' It also explains payment path choices: use USDC with a tx_hash or Stripe with a checkout link. It does not name an alternative tool but gives condition for invocation that is sufficient.

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