set_product_metafield

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

No annotations are provided, so the description must cover behavioral traits. It discloses the upsert behavior and the condition for using `type`. However, it does not mention potential side effects, idempotency, error handling, or rate limits, which would be valuable for a mutation tool.

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?

Two concise sentences with front-loaded action. No unnecessary words or repetition.

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?

The description covers the essential behavior and parameter guidance. It could be more complete by addressing error scenarios or what happens if the product doesn't exist, but it is sufficient for a tool with a well-documented schema.

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 coverage is 100%, so baseline is 3. The description adds value by explaining when to use the `type` parameter and specifying the GraphQL mutation. This goes beyond the schema's descriptions.

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 clearly states it creates or updates a metafield using the GraphQL `metafieldsSet` mutation (upsert). It distinguishes itself from sibling tools like `delete_product_metafield` and `get_product_metafield` by specifying the exact action and resource.

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?

The description provides clear usage context: it explains the upsert behavior and when to use the `type` parameter. However, it does not explicitly mention when not to use this tool or compare it to alternatives like `set_customer_metafield`, though the tool name and sibling list make this somewhat clear.

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