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

With no annotations present, the description carries the full burden of behavioral disclosure. It states the conceptual operation but does not reveal how inputs are supplied (the schema is empty), what the output looks like, whether this is a boolean check, or any assumptions about how ratios should be formatted. This is a significant transparency gap for a tool with zero schema guidance.

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?

The description is a single, tight sentence with no filler. The core operation is front-loaded and immediately scannable. The 'Analogous:' prefix is redundant with the tool name but harmless given the extreme brevity.

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 tool with no input schema and no output schema, the description is severely incomplete. An agent cannot determine how to invoke the tool, what arguments to provide, what result to expect, or how this differs from the many adjacent ratio/proportion tools. The one-sentence definition is not enough to make this tool reliably usable.

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?

With zero parameters, the schema provides no semantic guidance. The description adds the key domain concept — that the tool operates on 'two ratios' — which is the only meaningful clue available. Baseline 4 is appropriate for a 0-param tool, though the mismatch between the empty schema and the mention of two ratios is not reconciled.

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 clearly states a specific action — 'Check if two ratios are proportional' — with a clear verb and resource. It distinguishes this from obvious siblings like ratio-simplify and ratio-of by focusing on proportionality rather than simplification or conversion, though it doesn't name any alternative explicitly.

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 description gives no guidance on when to use this tool versus related tools such as x402-ratio-of, x402-proportion-of, or x402-is-close-to. No context, exclusions, or alternative routing is provided, leaving the agent to infer the intended use case from the name alone.

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