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

Annotations already declare readOnly, idempotent, and non-open-world behavior, so the bar is lower. The description adds the important default behavior that omitting both parameters turns this into a listing operation, plus a sketch of the response contents.

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 tightly packed sentence front-loads the resource, then the return contents, then the invocation modes. Very little waste, though the phrase 'a sample with both prices' is slightly cryptic about which two prices are meant.

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?

A simple two-optional-parameter read tool with full annotations and an output schema, so return values need no elaboration. The description covers lookup, search, and listing modes; only minor details like no-match behavior are unstated.

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 the baseline is 3, but the description goes further by explaining the either/or relationship between 'mint' and 'search' and what an empty call means. The one gap is that it does not explain how slug matching differs from the free-text search beyond the wording.

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 resource (mint or refiner, with concrete examples like Royal Canadian Mint and PAMP) and enumerates what is returned: country, summary, product count, and a priced sample. It is clearly distinct from siblings such as get_product or search_products.

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 covers the three input modes: a slug, search words, or omitting both to list mints. It does not name a competing sibling tool for the 'browse all mints' case, but the when-to-use conditions are otherwise unambiguous.

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