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: no edge-case behavior (zero weights, mismatched lengths), no output shape, no constraints. 'Median of weighted' adds no behavioral context at all.

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 not in an earned way – the single phrase is a tautological restatement rather than front-loaded substance. This is under-specification masquerading as conciseness.

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 tool with no annotations and no output schema, the description should at minimum explain accepted input format and return value. It explains neither, leaving an agent unable to call the tool confidently.

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 baseline is 3 per the rubric. However, both schema descriptions are vacuous ('Values to process', 'Weights to process'), and the description adds nothing about format (e.g., comma-separated string vs. array) or the requirement that the two lists align in 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 'Weighted Median: Median of weighted' essentially restates the tool name. It implies the operation is a weighted median, but does not state the resource, the input format, or distinguish it from near-identical siblings like x402-median, x402-weighted-mean, and x402-weighted-average.

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 alternatives. With siblings such as x402-median, x402-weighted-mean, and x402-weighted-average in the same family, the absence of any routing information is a serious gap.

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