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

No annotations are supplied, so the description carries the full behavioral burden. It does add one genuinely useful operational fact — 5 free trial calls per signed wallet, implying a paid/auth-gated call path — but says nothing about input format, what algorithm or precision the mean uses, how empty or non-numeric input is handled, or what the response looks like.

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 the brevity comes from under-specification rather than discipline, and the opening sentence is a duplicated restatement with a typo. The only informative clause (free trial calls) is buried after the filler instead of being paired with any functional detail.

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?

This is a one-parameter computational tool with no annotations and no output schema, so the description is the only place an agent can learn the input encoding and return shape. It supplies neither, leaving the definition effectively unusable without trial and error.

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 single "values" parameter is typed only as a string with no explanation. The description contributes nothing about how values should be encoded (comma-separated? JSON array? whitespace-delimited?), which is the single most important detail for invoking this tool correctly.

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?

"Mean Of: Mean of of." restates the tool name and contains a duplicated word ("of of"), so it reads as a tautology rather than a definition. An agent can infer this computes a mean, but it does not say of what (a list, a set of numbers, a distribution) nor distinguish it from the many mean-flavored siblings such as x402-sample-mean, x402-weighted-mean, or x402-trimmed-mean.

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 when-to-use guidance, no conditions, and no named alternative. With roughly a dozen sibling mean/central-tendency tools in the list, the absence of routing guidance leaves the agent with nothing to disambiguate selection.

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