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

Annotations already mark it read-only and closed-world; the description adds meaningful behavioral detail: how many observations Vortex has, that the percentile is withheld when the series is too short, and that stock-out and shipping changes are covered. No output schema or pagination specifics are provided, but the read-only annotation lowers the bar.

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 short, front-loaded with the main behavior, and every sentence earns its place: what it returns, when to call it, an edge-case behavior, and price. The phrasing is slightly awkward but structurally efficient.

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 two-parameter read-only tool with complete schema coverage, the description conveys the decision context, the key return categories, and an important edge case. It doesn't spell out exact output shapes, but no output schema exists and the stated information is enough to use it correctly.

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 description coverage is 100%, so the baseline is 3 even without additional parameter detail. The description mentions 'product' and 'series' but adds no semantic meaning beyond the schema's product URL and days 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 identifies the tool as returning historical price, stock, and shipping data for a product, including where today's price sits against its own record. It lacks an explicit verb phrase and does not name or differentiate sibling tools, so it stops short of a 5.

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?

"When to use: Call this when you have a candidate and want to know whether to buy now or wait" is explicit about the intended situation. It does not provide when-not-to-use guidance or name alternatives such as watch or report, so it earns a 4 rather than a 5.

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