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

With readOnlyHint already declaring the safety profile, the description adds useful context by specifying the resource locator (id or slug), supported options (expand, fields), and the exact REST endpoint. It does not discuss response format or errors, but for a read-only get operation, this is sufficient extra transparency beyond the annotation.

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 two sentences, each earning its place: the first states the core operation and scope, the second lists supported options and the endpoint. It is front-loaded, concise, and free of filler.

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 simple read-only tool with full parameter schema and a clear endpoint, the description covers the essential usage information. It does not detail the response shape, but the phrase 'Fetch a single product' implies the return value, and the absence of an output schema is compensated by the clear action and REST reference.

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%, with descriptions already explaining 'id or slug,' expand, and fields. The description only restates these parameter categories without adding new semantics, so it stays at the baseline score of 3.

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 uses the specific verb 'fetch' and identifies the resource as 'a single product by its record id or its slug,' clearly distinguishing it from list/create/update product tools. It also references the underlying REST endpoint, further disambiguating the action.

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?

The phrase 'Fetch a single product' makes the primary use case clear, and the sibling tool list shows there is a separate list_products for broader queries. However, it does not explicitly state when to prefer this over list_products or mention any constraints, so it lacks explicit exclusions or alternative guidance.

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