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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it discloses nothing: not the formula, not what the 'string' inputs should look like, not what is returned. For a zero-annotation computational tool this is a complete gap.

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?

It is short, but the brevity comes from under-specification rather than efficiency: the single phrase duplicates the tool name and conveys no information. Every sentence does not earn its place.

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?

With no annotations, no output schema, and a 2-parameter input schema whose field semantics (units, numeric strings, sign conventions) are non-obvious, the definition provides nothing an agent needs to invoke it correctly. It is wholly inadequate for the tool's complexity.

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 the schema already documents both parameters, making the baseline 3. The description adds zero meaning beyond the schema; the schema's own glosses ('Cogs to process', 'Revenue to process') are generic but present.

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 'Gross Margin: Gross Margin' simply restates the tool name with no verb or action, making it a tautology. An agent cannot tell from this text whether the tool computes a margin from inputs, looks one up, or formats one, nor how it differs from close siblings like x402-profit-margin, x402-operating-margin, or x402-margin-calc.

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?

There is no guidance on when to use this tool versus the many neighboring margin/finance tools, and no prerequisites are given. The agent must infer usage entirely from the name.

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