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

Beyond the annotations (readOnly, idempotent, non-destructive), it discloses that prices are 'AUD incl. GST', sourced identically to live prices to guarantee consistency, and that it 'never invent[s] a discount' when no breaks exist. These are valuable behavioral guarantees not captured in the annotations.

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 appropriately sized, with every sentence serving a purpose: definition, usage example, use case, currency/source caveat, and a no-invention guarantee. It is front-loaded with the core purpose and conveys all necessary information 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 (3 parameters, no output schema), the description covers all necessary aspects: what it does, when to use it, behavioral safeguards (currency, GST, source consistency, no fabricated discounts), and the input parameters. It is self-sufficient for an AI agent to correctly invoke the 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?

The schema already provides 100% coverage for all three parameters, so the baseline is 3. The description adds practical meaning by illustrating how the quantity parameter works ('1 → $135 ea, 2 → $132.30, 5 → $128.25') and explaining that the current quantity is used to 'highlight the next worthwhile break', enriching the plain schema definitions.

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 retrieves 'Vivid's REAL published volume price breaks for a product + size', with a concrete example of price tiers. It distinguishes itself from sibling tools like vivid_price by focusing on volume breaks and bulk/trade pricing, making its 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?

Explicitly states when to use: 'Use for bulk/trade pricing questions, or right after a price when a slightly larger quantity would save the customer money.' This provides clear context, though it does not explicitly name alternative tools or when-not-to-use scenarios, which would elevate it to a 5.

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