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

Adds real context beyond annotations: boundary behavior (A0/A10 return no counterpart), the exclusion of DL, and the per-call price with x402/Solana payment plus a free HTTPS endpoint. Annotations already cover readOnly/idempotent/non-destructive, so this is valuable supplementary information rather than a repeat.

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?

Front-loads the core behavior, then edge cases, then pricing and transport. Every sentence conveys new information; only the pricing/URL clause is tangential to selecting the tool, but it is short.

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 single-parameter, idempotent, read-only lookup with no output schema, the description covers what it returns conceptually (both neighboring sizes), edge cases, and cost. An agent has everything needed to call it and interpret the likely response.

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 coverage is 0%, so the description must carry the load; its examples ('A4', 'A3', 'A5', 'A0', 'A10', 'DL') effectively demonstrate the expected value format and pair with maxLength 8. However, it never explicitly says the single 'name' parameter is that paper designation, leaving the binding implicit.

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?

Uses a specific verb+resource: returns the next larger and smaller sheet in the same ISO series, illustrated with 'A4 sits between A3 and A5'. Clear on its own, but it never distinguishes itself from sibling tools paper_scale, paper_size, or paper_fit, so an agent must infer which paper tool to pick.

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?

Gives concrete usage boundaries — A0 has no larger, A10 has no smaller, DL is not in a series — which tells the agent exactly when input will yield no result. It stops short of naming an alternative tool for those cases or explicitly stating when to choose it over paper_scale.

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