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

With no annotations, the description carries the full behavioral burden. It usefully discloses the required auth header (x-wavepay-service-key with an mk_live_…/mk_test_… key), which is real context an agent needs, but it says nothing about read-only vs mutating behavior, pagination, rate limits, or response shape.

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 short sentences, scope front-loaded and the auth prerequisite second; every clause carries information and nothing is padded.

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?

For a no-parameter read tool with no output schema, the description covers what the catalog contains and how to authenticate, which is enough to invoke it correctly. The absence of any statement about read-only nature or result volume is a minor gap.

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 tool takes zero parameters, so the baseline of 4 applies and there is no parameter-level semantics to add beyond what the schema (an empty object) shows.

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 resource (the merchant's catalog) and enumerates its contents — sites, plans, prices, coupons — scoped to the caller's merchant key. It is clear what the tool returns, though it never explicitly distinguishes itself from the nearby wavepay_pricing sibling.

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?

Usage is implied by 'the sites, plans, prices and coupons your merchant key can see,' which tells an agent this is the merchant-scoped read surface. However, there is no statement of when to prefer it over wavepay_pricing or wavepay_providers, and no exclusions are given.

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