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

With no annotations and no output schema, the description carries the full behavioral burden, yet it reveals nothing about side effects, return format, data requirements, or any operational characteristics. The agent has zero information about how the tool behaves.

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 extremely short, but it is under-specified rather than concise—it simply repeats the name. It does not earn its place because it adds zero information; this is the same pattern as the 'Process' low example.

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?

The tool is completely opaque: no description of what it does, no parameters, no output schema, and no usage context. An agent could not determine how to invoke it correctly or interpret its result. This is inadequate even for a simple statistical utility.

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?

The input schema has zero parameters, so there is nothing for the description to explain beyond the schema. The baseline of 4 for 0 parameters applies, though the vacuous schema and missing context make this more of a formality than genuine helpfulness.

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 'Coefficient Of Variation: Coefficient Of Variation' is a tautology—it restates the tool name without adding a verb, resource, or any functional detail. It fails to state what the tool computes or returns, and does nothing to distinguish it from the near-duplicate sibling 'x402-coeff-variation'.

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 guidance is given about when to use this tool versus alternatives. There is no mention of input requirements, appropriate contexts, or exclusions, leaving the agent completely without orientation.

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