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

With no annotations, the description carries the full behavioral burden, but it only states the multiplication formula. It does not disclose units, validation behavior, what the tool returns, or any side effects; the implied pure-calculator behavior is not enough to be a complete contract.

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 text is short, front-loaded with the formula, and contains no wasted sentences beyond the redundant 'Impulse:' prefix. It is easy to scan.

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 tool with no schema parameters and no output schema, the description should explain how values are supplied, expected units, and what result to expect. None of these are provided, and the schema-description mismatch is a significant gap.

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 description does add meaning beyond the empty schema by naming force and time as the inputs. However, it conflicts with an input schema that declares no properties and leaves units and types unspecified, making the parameter contract ambiguous.

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 clearly states the operation and formula: it calculates impulse as force multiplied by time. This is unambiguous even among hundreds of physics and math siblings, but it does not explicitly contrast with alternatives such as x402-force, x402-momentum, or x402-acceleration.

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 about when to choose impulse over related calculators or when not to use it. 'Provide force and time values' is an input instruction, not a selection criterion.

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