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

Annotations already declare the tool as read-only, idempotent, and non-destructive, so the description doesn't need to reiterate safety. It adds valuable context by enumerating the types of information available (shipping, returns, warranty, etc.), which helps the agent know what queries it can answer. Slight gap: no mention of output format or structure, but the existence of an output schema mitigates this.

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 that front-loads the core purpose. It lists many topics efficiently, but the long list could be structured more clearly (e.g., using bullet points or a colon-separated list). Still, it is concise and every phrase contributes to 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?

Given the tool's simplicity (no params, clear policy-related scope) and the presence of an output schema (which handles return details), the description fully covers what the agent needs to know: what the tool provides and when to use it. It is complete and self-sufficient.

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 tool has zero parameters and no required fields, so the schema is trivially covered (100%). The description doesn't need to explain parameters. Per scoring guidelines, 0 params warrants a baseline of 4; the description adds no parameter-specific info, which is acceptable given the absence of parameters.

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 tool's purpose: providing 25karats brand facts and policies for shoppers, listing specific topics (shipping, returns, warranty, etc.). It distinguishes itself from sibling tools (which focus on products/diamonds) by targeting store-level policy information.

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 instructs when to use the tool: 'Call this before answering policy questions rather than guessing.' This provides clear guidance on when to invoke it and implicitly suggests not relying on assumptions, effectively covering when-not situations.

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