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

No annotations are provided, so the description carries the full burden. It only says 'calculators' and does not disclose whether it computes final price, amount saved, percentage, or both, nor does it mention output format or side effects.

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 short but under-specified rather than appropriately concise. One sentence is efficient, but it lacks enough substance to count as well-structured or front-loaded with useful information.

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?

With no output schema and no annotations, the description leaves major gaps: it does not clarify the calculation mode, return value, or whether one or both parameters are needed. Minimal but not complete enough for an agent to use confidently.

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 schema covers both parameters with descriptions, and schema coverage is 100%, so the baseline is 3. The description adds no additional meaning about formats, relationships, or expected input types beyond the schema.

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 says the tool offers discount and percentage calculators, so an agent can infer the domain. However, it lacks a specific verb or exact operation, and does not distinguish itself from siblings like x402-discount-calc or x402-percentage-change.

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 on when to use this tool versus alternatives. With hundreds of sibling calculator tools, the description provides no selection criteria or context that would help an agent choose this one.

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