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

With no annotations, the description carries the full behavioral burden and does well: it warns that the merchant key is returned only once and that only its hash is persisted, plus discloses a free-tier quota of 25 payments per 30 days. It omits auth requirements and duplicate-registration behavior, keeping it short of a 5.

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?

Three short sentences, front-loaded with the action and immediately followed by the most consequential facts (one-time key, quota). Every sentence earns its place with no filler.

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?

There is no output schema, and the description compensates by explaining the critical return value (single-use merchant key) and the free-tier limit. It stops short of covering failure modes such as duplicate emails or validation errors, but is otherwise complete for a two-parameter registration tool.

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 description coverage is 100%, so both parameters (name, ownerEmail) are already documented in the schema. The description adds no parameter-level detail, making the baseline 3 correct.

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 ('Register a WavePay merchant account') in the first sentence, which is unambiguous against siblings like wavepay_checkout, wavepay_catalog, and wavepay_pricing. An agent can tell this is the account-creation tool without opening any schema.

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 purpose implies onboarding use, but there is no explicit when-to-use guidance, no prerequisites, and no mention of what to do if a merchant already exists. With no competing registration sibling, the implied usage is adequate but sparse.

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