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

Annotations already carry readOnly/idempotent/non-destructive/closed-world, so the description's job is to add context beyond that—which it does by disclosing dual pricing (check/wire vs card/PayPal at +5%) and in/out-of-stock reporting. It doesn't cover pagination limits or result caps, but the added pricing behavior is genuinely useful beyond 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?

Three tight sentences, front-loaded with what is searched, then filters/sort, then the usage cue. No filler or restated title.

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?

An output schema exists, so return-value detail is optional, and the description still usefully flags the dual pricing model. Minor gaps remain: the type enum also includes grain and set, which the description's "coins, bars and rounds" omits, and pagination is unaddressed for a 9-parameter 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?

Schema coverage is 78%, so baseline is 3. The description restates the main filter axes (metal, type, price range, stock) and sort options but adds no syntax, default, or interaction detail beyond the schema, and never mentions query, page, or per_page.

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?

Specific verb+resource: searches the Bullion Trading LLC catalog, naming the four metals and the product forms covered. It is clearly distinguishable from siblings like get_product (single item), find_bullion, and list_best_sellers because it is the general filtered catalog search.

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 the use case ("when the user wants to find or compare Bullion Trading LLC products") and a negative constraint (cannot add to cart or place an order). It stops short of naming sibling alternatives such as find_bullion or get_product for single-item lookups, so routing to the closest alternative is still left to inference.

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