add_variants

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

Annotations only provide openWorldHint=true, so the description must carry behavioral disclosure. It adds useful context ('split primitive', auto-resolution of provider_variant_ids, the AQUA-vs-Navy trap warning, and the sync prerequisite). It does not, however, describe failure behavior when provider ids cannot be resolved or what the operation mutates on an existing product.

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?

Four short sentences, front-loaded with the core action and then constraints. The stray '[#c9cff4]' artifact at the end is noise that does not earn its place, and '(split primitive)' is jargon-y, but overall the structure is efficient.

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 a 4-parameter mutation tool, no output schema, and only 25% schema coverage, the description covers the trickiest field (provider_variant_ids) and one guard rail but omits context for workspace, price, and overall success/error behavior. Adequate but with real gaps for an agent to invoke correctly on first try.

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 25%, and only product_ref_id has a schema description. The description partially compensates by explaining that provider_variant_ids get resolved by color+size (or passed explicitly) and that product_ref_id enables the AQUA-vs-Navy guard. It says nothing about workspace, price, or the color/sizes semantics, leaving gaps.

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: 'Add variants to an existing product.' The '(split primitive)' note hints at its compositional role, but it is somewhat cryptic. It is clearly distinguishable from sibling tools like create_product and sync_to_fulfillment, which handle product creation and sync rather than variant addition.

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?

'Variants must exist before syncing' gives an implied ordering prerequisite, and the resolution-by-color+size note hints at the expected usage path. However, no explicit when-not-to-use or named alternative exists, so the guidance is implied rather than stated.

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