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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds useful behavioral context by indicating that price data is a 'live price range', which implies currency and variability, and that the call returns one diamond. It does not disclose output format or error behavior, so it does not exceed the baseline significantly.

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 a single, information-dense sentence. It front-loads the core purpose, then adds the key scoping detail about id provenance. There is no extraneous wording.

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, read-only lookup tool, the description gives sufficient context for an agent to know what to expect: details plus a live price range. With no output schema, it could add more on return structure or failure behavior, but the core invocation context is clear and complete enough.

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 only describes id as an integer with a minimum of 1, but the description adds critical meaning: this is a Carat Hunter id and it can be obtained from search_diamonds or a carathunter.com URL. This provenance is valuable and goes beyond the schema, though it does not specify how to extract or format the id from a URL.

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 clearly states the action: retrieving details and a live price range for one diamond by a specific Carat Hunter id. It also distinguishes this from search_diamonds by specifying the input source, making the purpose 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 description implies when to use this tool: after obtaining a Carat Hunter id from search_diamonds or a carathunter.com URL. It names a relevant sibling and provides clear context, though it does not explicitly rule out alternatives or state when not to use this tool.

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