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

Annotations already declare destructiveHint=true and openWorldHint=true, but the description adds the concrete damage model: sending options/variants 'replaces the whole set' and non-matching variants 'are dropped along with their stock counters.' It also discloses the -1 sentinel that preserves current price and compare-at values, which no annotation conveys.

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 destructive-replacement warning is front-loaded before the argument list, which is the right ordering for an agent scanning for risk. The args block is long but each line earns its place given 0% schema coverage; the only fat is the near-tautological opening sentence 'Update a product.'

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 26-parameter destructive mutation with an output schema (so return values need no explanation), the description covers partial-update semantics, replacement hazards, sentinel values, enumerated field values, and safer alternatives. Nothing an agent needs to invoke it correctly is missing.

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 0%, so the description carries the entire burden and does so: it documents all 26 parameters, enumerates allowed values for product_type, pricing_type, and status, explains the -1 keep-current convention, and flags which fields replace rather than merge (highlights, faqs, gallery, options, variants, JSON blocks).

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 ('Update a product') and immediately qualifies it with partial-update semantics ('Only the arguments you set are changed'), which is the key distinguishing behavior. It names two alternative tools, though it does not differentiate against the other update siblings (update_commerce_price, update_commerce_inventory, update_commerce_variant) that also touch product state.

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?

Gives a clear when-to-use-otherwise condition: 'Use set_commerce_product_options or the variant tools for safer, targeted edits,' which routes the agent away from this tool for narrow option/variant edits. There is no explicit guidance on when to prefer update_commerce_price or update_commerce_inventory, so the exclusion set is incomplete.

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