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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely new operational context not present in structured fields: a price of $0.001 USDC per successful call via x402 on Solana, plus an equivalent HTTPS GET endpoint. It also discloses the rotation-permitted rule and the sub-1 scale consequence, though it says nothing about the return shape.

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 purpose is front-loaded, and the pricing/endpoint sentence carries real information. However, the two opening sentences are circular ('a scale... places one sheet on another') and could be said in one clear line, so the phrasing costs readability without adding precision.

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-input computational tool with no output schema, the description partially covers the return value by saying the scale is 'an exact ratio of the millimeter sides'. The critical missing piece is input format and argument ordering, which is exactly what an agent needs before calling a tool with 0% schema documentation.

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% – both required parameters 'sheet' and 'onto' are bare strings with maxLength 8 and no documentation. The description at best implies these are paper sheets measured in millimeters, but never states the expected format (e.g. 'A4', 'letter') or that argument order matters (which sheet is placed onto which). With zero schema coverage, the description needed to compensate fully and does not.

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 does convey a specific operation – computing the largest scale ratio that fits one paper sheet onto another, allowing rotation – but it is phrased obliquely ('The largest scale that places one sheet on another, turning it when that lets it be larger') rather than as a plain verb+resource. It never distinguishes itself from close siblings like paper_fit, paper_size, paperfold, or paper_next, so an agent must infer the difference from name alone.

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 explicit statement of when to use this tool versus paper_fit or paper_size, and no prerequisites or exclusions. The clause 'Below one, the sheet has to shrink' hints at behavior in the downscaling case but is a result condition, not usage guidance.

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