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

The description adds real context the annotations don't: a $0.20 cost and the explicit refusal to make remedy or safety conclusions. However, 'Purchase' implies a monetary side effect that readOnlyHint=true and idempotentHint=true do not convey, and there is no detail on latency, rate limits, or what the package returns.

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?

One compact sentence with the cost and the scope disclaimer front-loaded; no filler. It is under-specified rather than bloated, which is a completeness problem, not a conciseness one.

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?

With no output schema, no annotation detail on returns, and 0% schema coverage, the description should explain what an 'evidence package' contains and what product_token identifies. Instead it leaves the core mechanics and the relationship to sibling tools undefined.

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 0% for the single required product_token, so the description must compensate and it does not — it never mentions the parameter, its format, or where its value comes from. Only the bare type is available to the caller.

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 names the domain (CPSC hazard/remedy evidence) and discloses a price, but the verb 'Purchase' is odd for a tool named build_..._evidence and 'evidence package' is an abstraction. Nothing distinguishes it from the siblings match_product_recall or resolve_consumer_product, so an agent can't tell which to pick.

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?

There is no statement of when to call this versus match_product_recall or resolve_consumer_product, and no hint that product_token likely comes from resolve_consumer_product. The only guidance given is negative scope ('no individual-unit remedy completion'), which limits claims rather than directing usage.

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