paper_size_reference

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

No annotations provided, so description carries full burden. It discloses that it returns all sizes if no size given and provides dimensions in both mm and inches. Lacks mention of any limitations or side effects, but as a read-only lookup, this is acceptable.

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?

Description is extremely concise: 4 sentences with front-loaded purpose and a separate parameters section. Every sentence adds value without redundancy.

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?

Given the tool's simplicity (1 param, no annotations, output schema exists), description covers key behaviors. Could mention that it supports both metric and imperial units explicitly, but overall sufficient for a lookup tool.

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 description compensates fully. It explains the 'size' parameter with concrete examples ('A4', 'Letter', 'Legal', 'B5', 'C4') and clarifies behavior for empty string. Adds significant meaning beyond the bare 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?

Description clearly states action ('Look up') and resource ('standard paper sizes') with specific series (ISO A, B, C, US). Distinguishes from sibling tools by being exclusively about paper sizes.

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?

Explicitly states when to use ('find dimensions in mm and inches') and behavior for empty parameter. Does not explicitly mention alternatives or when not to use, but context implies specialization.

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