Get variant

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

The readOnlyHint annotation already discloses the non-destructive nature; the description adds value by listing the fields returned and explaining the relative_link_url handling. It does not contradict annotations and provides practical context beyond the annotation, making the behavior clear for an agent.

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, front-loaded with the core purpose and followed by a single additional piece of practical context. Every sentence earns its place; no filler or redundancy. Very concise and well-structured.

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 get-by-ID tool with no output schema, the description covers the key expectations: what fields are returned and how to handle the relative_link_url. It also mentions an alternative tool. Missing some details like error handling or pagination, but those are rarely needed for a single-get tool. Small gap exists in clarifying when to choose list_variants over this, but overall sufficient.

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% for the single parameter id, which is described as 'Variant ID (UUID).' The description adds no further meaning to the id parameter itself; it only explains response fields. With high schema coverage, a baseline of 3 is appropriate.

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 states 'Get a single variant by its ID' which is a specific verb and resource, and enumerates the returned fields (name, SKU, pricing, stocks, media, status). This clearly distinguishes it from list_variants (multiple) and other variant operations. No ambiguity about what the tool does.

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 gives a concrete usage nuance: explains how to construct a full storefront link from relative_link_url and points to list_variant_links as an alternative for the joined link. However, it does not explicitly state when to prefer this tool over list_variants or get_product, though the single-vs-multiple distinction is implicit. Decent guidance but not exhaustive.

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