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

No annotations are supplied, so the description carries the burden; it discloses the pricing/quota behavior (5 free trial calls per signed wallet), which is useful context. But it does not state that this is a pure, side-effect-free computation or describe the return value format, which matters without annotations.

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?

Short and front-loaded: the computation is stated first, then the quota note. The emoji quota aside is slightly promotional but not wasteful.

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 two-param pure calculator with no annotations and no output schema, the definition covers the operation but omits return-format expectations and parameter format, leaving modest gaps an agent would prefer filled.

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 0%, so the description must compensate. It partially does by embedding cost and revenue in the formula, but adds no format detail (both params are strings) such as decimal vs. currency-string expectations or required-ness.

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?

Clear verb+resource: "Computes profit margin percent" and it even states the formula. However, it does not differentiate from close siblings like x402-gross-margin or x402-margin-calc, leaving the agent to guess which margin variant to pick.

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?

No when-to-use guidance, prerequisites, or named alternatives. The only extra sentence concerns the free-trial quota, which is billing context rather than selection guidance.

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