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 discloses the formula, implying a pure side-effect-free calculation, but says nothing about units (N·s vs. lb·s), accepted input formats, precision, or what happens with missing/zero inputs — notable since both parameters are technically optional.

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?

Two short sentences with the core operation front-loaded, no padding. There is mild redundancy in restating force and time after already defining the formula, which keeps it from a 5.

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 low-complexity, side-effect-free arithmetic tool with no output schema, the description is minimally adequate: it states the computation. The omission of units and result format is the main gap, but it is small relative to the tool's simplicity.

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 baseline is 3 per the rubric. The schema's own descriptions are near-placeholders ('Force to process'), and the tool description adds no unit, type, or format meaning beyond naming the two quantities, so it neither compensates nor regresses.

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?

Names a specific verb and physics quantity and gives the exact formula (force × time), which lets an agent identify the computation. It does not, however, distinguish itself from closely related siblings such as x402-momentum, x402-force, or x402-work, so it falls short of a 5.

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 (e.g., momentum, kinetic-energy, force-unit) and no conditions, prerequisites, or exclusions. The only usage instruction is the bare 'Provide force and time values,' which is a parameter restatement, not guidance.

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