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

With readOnlyHint and openWorldHint already covering the safety profile, the description adds genuinely non-redundant context: the upstream source is acehardware.com via a residential proxy, and billing is $0.02 USDC per successful call via x402 with failed calls not charged. It stops short of stating rate limits or per-page result caps relative to the 1-20 page range, which keeps it at 4 rather than 5.

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?

Two sentences, front-loaded with what the tool does and followed by cost/access terms. The return-field enumeration is dense but each field is a distinct, useful signal; nothing is filler, though the list is long enough to be slightly scannability-heavy.

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?

Output schema exists, so the field list is surplus rather than required, and all remaining agent needs (source, proxy, pagination size, cost model, failure billing) are covered. Only a note on rate limits or result freshness would add more.

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 coverage is 100%, so both parameters are already documented, making 3 the baseline. The description earns one extra point by quantifying 'up to 30 products per page', which clarifies what a page step actually yields — information absent from the schema.

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?

States a specific verb and resource ('Ace Hardware (US) product search') and pins the retailer domain, which is exactly what distinguishes it among dozens of ecommerce_* siblings. An agent can tell this is the Ace Hardware-specific search rather than a generic or other-retailer search without opening the schema.

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?

Usage is implied by naming the retailer and the payload ('search words, e.g. cordless drill, paint roller' in the schema), so an agent can infer when this tool is the right one. However, it never states when NOT to use it, nor routes to a sibling (e.g. price comparison or other hardware retailers) for alternative needs.

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