Get API key

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

Annotations only declare non-read-only, non-idempotent, non-destructive, which fits minting but says little. The description adds the real behavioral picture: rate limit of 10 new keys per caller IP per UTC day, allowance raised 100 to 1,000/day, free and not an x402 check, plaintext returned once only with SHA-256 hash stored, and that a new key does not change any merchant score.

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-loaded with the core action and impact in the first sentence, then usage, then constraints. Slightly long at four paragraphs and some cost/rate-limit detail could be tightened, but nearly 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?

No output schema exists, and the description compensates by enumerating the returned fields and flagging that the plaintext key is shown only once. Combined with the rate limits, cost model, and misuse warnings, an agent has everything needed to call it 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?

No input parameters, so the baseline is 4. The description instead documents the return contract (api_key, token_type, daily_limit, prefix, note), which is useful but belongs to the output side, not parameter semantics.

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 ('Mint one free PayCheck API key') plus the resulting artifact and its effect on the allowance. The agent can distinguish this from check_merchant and get_quota, which consume the key rather than create it.

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?

Explicit when-to-use ('once when you set up a long-running agent, then store the key and pass it on later check_merchant or get_quota calls') and explicit when-not-to-use ('Do not call this every turn. Do not call it to score a payee or to dodge a block verdict'). Names the sibling tools that consume the key.

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