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

No annotations are provided, so the description carries the full behavioral burden. It says nothing about determinism, input format expectations, edge cases (empty list, single value), or how the result is returned. For a computation tool this is a notable gap, though the operation is intrinsically simple and non-destructive.

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 short fragment with no wasted words and is front-loaded. However, its brevity comes at the cost of under-specification rather than efficiency; there is no structure beyond a name and a gloss.

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 one-parameter statistics tool with no output schema, the description still omits the most practically important detail: how the input values are supplied and formatted in a plain string field labeled only 'Values to process'. Nothing about the expected result form is conveyed either.

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 the single 'values' parameter, establishing a baseline of 3. The description adds no format or encoding detail (e.g. delimiter, array vs string) beyond what the schema provides, so it neither helps nor compensates.

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 'Median Absolute Deviation: Median of absolute deviation' essentially restates the tool name and title without adding a distinct verb or scope. It does not distinguish this statistic from close siblings such as x402-mean-abs-deviation, x402-median, or x402-quartile-deviation. This is a near-tautology rather than an explanatory purpose statement.

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 statement of when to use this tool versus alternatives, nor any mention of the surrounding statistical tools a caller would plausibly confuse it with. No prerequisites, exclusions, or context are given. The agent is left to 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.