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

With no annotations, the description carries the full burden. It discloses only that there are 5 free trial calls per signed wallet — a genuine auth/cost detail — but says nothing about output shape, whether confidence intervals or a p-value accompany the ratio, or how the four counts are interpreted.

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 fragments with no filler, front-loaded with the tool's subject. However, the brevity reflects under-specification rather than efficiency, and the emoji/free-trial line consumes half the text without helping the agent call the tool.

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?

A four-parameter statistical calculator with no annotations, no output schema, and no formula description is under-documented. The agent must guess both the input encoding and what the response contains, which is risky for a numerical epidemiology 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 0% and the description adds no parameter meaning at all. The four string fields (exposedCases, unexposedCases, exposedControls, unexposedControls) are left entirely to the caller's inference, including their expected format (counts vs. comma-separated values) and whether any are required.

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?

"Odds Ratio: Ratio of odds" restates the tool name rather than describing an operation — there is no verb (compute/calculate) and no indication that it consumes a 2x2 exposure table. An agent can guess the statistical concept but cannot tell how it differs from siblings such as x402-relative-risk or x402-relative-risk-style tools.

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, no prerequisites, no named alternative. The only contextual sentence concerns billing, not invocation, so the agent receives zero help choosing this tool over the many adjacent statistics tools in the sibling list.

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