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

With no annotations provided, the description carries the full disclosure burden and delivers none of it. It does not state input format (comma-separated? space-separated numeric strings?), error behavior on mismatched values/weights lengths, or anything about the result. A single tautological sentence leaves behavior entirely opaque.

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 this is under-specification rather than conciseness. The entire content is a restated name with no front-loaded substance to earn its 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 2-parameter math utility with no annotations and no output schema, the description should at minimum document the input encoding of the string parameters. Nothing an agent needs to invoke it correctly is provided.

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%, which sets the baseline at 3 under the rubric. However, the schema fields themselves are near-useless ("Values to process", "Weights to process"), and the description adds nothing — notably it does not clarify the expected string format or that values and weights must be equal-length.

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 restates the tool name rather than explaining it: "Weighted Mean: Mean of weighted" is circular and adds no information beyond the title. It does not distinguish this tool from close siblings such as x402-weighted-average, x402-weighted-median, x402-mean-of, or x402-harmonic-mean, all of which appear in the same family.

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 whatsoever on when to use this tool versus the many nearby alternatives (weighted-average, weighted-median, trimmed-mean, winsorized-mean). No prerequisites, no exclusions, no context — the agent must guess 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.