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

The annotations already mark destructiveHint=true, and the description adds meaningful context on top: writes go to the store, sku/barcode/weight are per-variant so variantId is required for multi-variant products, batch calls are capped at 25 updates, and each update returns previous and applied values plus the product's new score. This goes beyond the bare annotation without contradicting it.

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 sentences with no filler: purpose, usage trigger, per-variant constraint, and batch/return behavior are all packed tightly. The most important discriminator ('merchant-supplied physical facts') is front-loaded, and every clause adds operational value.

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 mutation tool with one nested-array parameter and no output schema, the description covers the essential operational details: what is written, when to use it, the variantId requirement, the 25-item limit, and what the response returns. It does not cover error conditions or ordering guarantees, but those are not critical for selecting and invoking this tool 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 0%, so the description carries the parameter-meaning burden. It explains the domain purpose of sku, barcode, weight, and brand, clarifies that these are per-variant when variantId is needed, and notes the max of 25 items. It does not deeply explain weightUnit or the shape of each update object, but the schema provides some nested property descriptions and the description compensates for the main 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?

The description opens with a specific action and resource: 'Write merchant-supplied physical facts to the store', then enumerates the exact fields (SKU, barcode, weight, brand). It also distinguishes the tool from enrichment-based siblings by calling these the gaps Pollen cannot fill, so an agent can reliably tell it apart from enrich_product or enrich_all_products.

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?

It gives an explicit trigger: 'Use when the merchant provides values', with concrete examples like 'all tees weigh 180 grams' and 'barcodes from my supplier sheet'. This clearly states when the tool is appropriate. It implies the counterpart (do not use when enrichment can supply the data) but does not explicitly name an alternative sibling or say 'do not use for enrichment-derived values', so it stops short of a 5.

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