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 and discloses essentially nothing: no formula, no unit conventions (watts vs kilowatts), no handling of missing inputs, no return shape. The trial-call note is commercial, not behavioral.

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 shortness here reflects under-specification rather than economy—the title line is redundant with the tool name and the only other sentence is an unrelated promotional note.

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 two-parameter calculation tool with no annotations and no output schema, the description should at minimum state the computed quantity, its units, and how the two inputs combine. None of that is present.

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% with two parameters (current, voltage) that are undocumented in the schema. The phrase "Power of v i" weakly hints that the inputs are voltage and current, but says nothing about units, accepted formats, or which parameter is which.

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?

"Power V I: Power of v i" restates the tool name rather than describing the operation; an agent must infer from the input schema (current, voltage) that this computes electrical power P = V × I. It does not distinguish itself from siblings such as x402-electric-power or x402-power.

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?

The only extra text is a pricing note about 5 free trial calls per signed wallet, which is not when-to-use guidance. There is no indication of context, prerequisites, or which of the many power-related siblings to prefer.

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