Update Shopify Product

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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so safety is covered. The description adds genuine non-redundant behavior: partial-patch semantics ('Only provided fields change') and the GID requirement for variant updates. It stops short of describing error/return behavior, which keeps it at a 4.

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 tight sentences, front-loaded with the mutable field list, followed by the patch-semantics constraint and then the sibling routing. No filler.

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 10 parameters, nested variant objects, no output schema, and near-zero schema descriptions, the definition covers the majority of the mutation surface and the add/update/delete variant distinction well, but omits several scalar fields (handle, productType, descriptionHtml) and variant sub-fields an agent may need to populate correctly.

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 10%, so the description must carry the load. It maps the main parameter groups (title, description, SEO, status, vendor, tags, variants) and clarifies the variant id semantics, but handle, productType, descriptionHtml, and the variant-level barcode/compareAtPrice/inventoryPolicy fields are left undocumented in both places.

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 (Update) plus resource (Shopify product) and enumerates the mutable surface: title, description, SEO, status, vendor, tags, variant prices/SKUs. It also distinguishes itself from shopify_create_variants and shopify_delete_variants by declaring that variants passed here are updated in place.

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?

Explicitly routes the agent: update existing variants here, add via shopify_create_variants, remove via shopify_delete_variants, and each variant requires its GID. It does not, however, address when to prefer shopify_bulk_update_variants over this tool for multi-product variant edits.

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