update-variant-price

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

No annotations are provided, so the description must disclose side effects. It conveys that the operation mutates variant pricing, but it does not mention whether the price is overwritten, whether omitted compareAtPrice is cleared or preserved, validation behavior, or permission requirements. For a mutation tool, this is a significant transparency gap.

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 a single front-loaded sentence with no filler. It states the core operation and the one key option (compare-at price) immediately, earning its place.

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 small mutation tool with 100% schema coverage, the purpose and parameters are adequately documented. However, with no annotations and no output schema, the description does not cover behavioral expectations or return values, leaving a moderate completeness gap that prevents a higher score.

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 documentation covers all four parameters, including the decimal-string format and accepted variant ID forms, so the baseline is 3. The description adds only the optionality of compare-at price, which is already reflected by the schema's required list, so no meaningful new parameter semantics are contributed.

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 a specific action (Update), a precise resource (product variant), and the target fields (price, optionally compare-at price). This clearly differentiates it from sibling update-product, which operates at the product level, and from adjust-inventory, which handles stock rather than pricing.

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 intended use is implied by the action: call this when a variant's price or compare-at price needs to change. However, it does not explicitly state when to prefer this over update-product or exclude product-level updates, leaving some routing inference to the agent.

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