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

This is the definition's strongest contribution: it discloses the two-phase confirmation workflow, that the call itself is non-mutating, and what it returns (a preview of changes plus a confirmation link). That goes well beyond the annotations, which only say readOnlyHint=false and destructiveHint=false. There is mild tension between 'calling this changes nothing' and readOnlyHint=false, but the surrounding text explains the deferred write clearly enough that it is not a contradiction.

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, each carrying distinct information: what it sets, the money format, the no-side-effect behavior, and who can commit the change. The most surprising and important fact (no change happens on call) is placed prominently.

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 no output schema, the description correctly spends words on the return value (preview plus confirmation link), which an agent otherwise could not anticipate. The one notable omission is that the variants list is a full replacement where omitted variants are deleted – a destructive consequence that is currently only in the schema description.

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 50%, but the description adds the meaningful convention that all money values are integer minor units (cents), which an agent must know to pass price correctly. Beyond that it adds little parameter detail – the richer variant semantics (omitted variant is removed, picture numbering, price/stock defaults) live in the schema's own description rather than the tool description.

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 a concrete verb and resource: set a product's options (variants) and each variant's picture. It is distinguishable from products_edit and products_bulk_price_edit by implication, but it never names those siblings or states how the scope differs, so sibling disambiguation is left to inference.

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 conveys the critical usage context that calling the tool performs no change and only produces a preview plus a confirmation link the merchant must act on. However, it offers no guidance on when to prefer this over products_edit for options or products_bulk_price_edit for prices, and no exclusions.

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