create_variant

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It mentions the primary inputs (options + prices) but does not disclose whether this requires product ownership/permissions, whether existing variants are replaced or appended, inventory implications, or behavior of optional fields like manage_inventory and sku. For a mutation tool with zero annotation coverage, key behaviors remain opaque.

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 compact two-sentence structure that front-loads the core action and includes a concrete, useful example. It's efficient with few wasted words, though it could be expanded to cover critical behaviors without becoming bloated.

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?

With 6 parameters, no output schema, no annotations, and no guidance on return values or side effects, the description is insufficient for a mutation tool. It covers options and prices but leaves sku, manage_inventory, and title semantics undocumented, and gives no sense of what the response contains or error conditions to expect.

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 only 17%, and the description partially compensates by explaining options (map of option title->value) and prices (array of {amount, currency_code}) with a concrete example. However, it doesn't clarify sku, manage_inventory, or title semantics beyond what the schema shows, leaving several parameters under-specified.

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 'Add a variant to an existing product' with a specific verb+resource, clearly defining the action. It also implicitly differentiates from siblings like create_product and update_variant by specifying it adds to an existing product, though it doesn't explicitly name alternative tools.

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 context ('Add a variant to an existing product') but provides no exclusions or explicit when/not-to-use guidance. It doesn't differentiate from update_variant or delete_variant for the agent, though the example usage gives practical framing.

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