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

Annotations already establish read-only, idempotent, non-destructive behavior, so the bar is low. The description adds meaningful context about the result: the calculation is tiered 'by band', includes 'the cap', and names 'who collects it' — output-shaping detail the annotations cannot convey.

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?

A single tightly packed sentence with the essential scope front-loaded. Minor waste in the opening clause, which duplicates the title rather than advancing the agent's understanding.

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 one-parameter, no-output-schema calculator, the description covers the input domain, the tiered computation, the cap, and the beneficiary — everything needed to invoke it and anticipate the result. Nothing material is missing.

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?

Only one parameter exists and schema coverage is 100% ('Resale price in pounds.'), so the schema fully documents it. The description adds only the implicit currency/context ('UK resale'), matching the baseline for high-coverage schemas.

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?

States a specific computation ('royalty owed to an artist on a UK resale') with the domain named, which is enough to separate it from siblings like price_commission or get_fair_art_price. The first clause largely restates the title, so it isn't maximally efficient, but the verb+resource is unambiguous.

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?

The phrase 'on a UK resale through a gallery, dealer or auction house' implies the applicable scenario and implicitly scopes to UK resales, but there is no explicit when-to-use, when-not, or named alternative to pick instead. Usage must be inferred from the domain framing.

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