add-product-media

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

With no annotations at all, the description carries the full burden and does disclose a genuinely non-obvious behavior: media is processed asynchronously and items return as UPLOADED or PROCESSING rather than READY. That prevents an agent from misreporting success. It still omits auth/scope requirements, failure handling for unreachable URLs, and whether re-adding the same URL duplicates media.

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 short sentences, front-loaded with the action, then the async caveat, then the verification pointer. Every sentence contributes information an agent needs; 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?

For a low-complexity 2-parameter tool with no output schema and no annotations, the description covers the action, the URL requirement, the async lifecycle, and the verification path. The main remaining gap is what the call itself returns (media IDs/statuses) and error behavior for invalid or private URLs.

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%, with productId's GID format and originalSource's 'publicly accessible image URL' both documented in-schema, so the baseline is 3. The description reinforces the public-URL requirement for media but adds nothing about the 'alt' field or array semantics beyond the schema.

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 ('Attach images to an existing product') and adds a hard constraint ('by public URL') that distinguishes it from any upload-from-file or update-product tool. Among the many product siblings (create-product, update-product, manage-product-variants, get-product-media), it is unambiguous which job this performs.

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 to get-product-media as the follow-up verification step once media is added, which is real alternative-aware guidance. It does not say when *not* to use it (e.g. that media cannot be attached to a nonexistent product) or whether it appends rather than replaces existing media, 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.