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

readOnlyHint=true already declares this a safe read, so the bar is lower; the description adds genuinely useful context — the required V3 token and the underlying GET endpoint. It does not describe the response shape or error behavior, but the auth requirement is a meaningful addition 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 compact sentences with zero filler; the identifying scope ('One product or service by V3 id') is front-loaded, followed by the prerequisites and endpoint. Every sentence carries distinct information.

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 getter with no output schema, the description covers identification, auth, and the endpoint, but never says what is returned (fields, not-found behavior, or whether it errors on a missing product). That gap is minor but real given there is no output schema to fall back on.

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 100% with only one param, so the schema already documents 'id' fully, including the prod_ pattern. The description repeats the 'prod_...' format without adding syntax or lookup guidance beyond what the schema states, so baseline 3 applies.

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 (retrieve one product/service) and scopes it precisely by the V3 id format 'prod_...'. The singular 'One product or service' implicitly contrasts with the sibling list_products, but no sibling is named explicitly, so it stops short of full differentiation.

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 description implies usage (fetch a single known product by id) and states a prerequisite (API V3 token), but gives no explicit when-to-use vs when-not guidance. It never names list_products as the way to obtain the id, leaving routing to inference.

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